Yes, i know the title seems like it originates from a generic youtube rantsona video. But i really wanted to share this tought.
In Beginning Of The End Celestia mentions "everything you have gone through over the years has been a training program" to Twilight Sparkle. Some have been saying what Discord did to the trio was the same as Celestia did for years, but others argued the difference is Celestia did not free and abuse criminals, they escaped from their prisons by themselves and needed to be recontained. But there is another thing that seems to be overlooked: what Celestia said does not make any sense. Let's recap.

1. NIGHTMARE MOON: Twilight Sparkle was the one who warned Celestia about her, then she replied back with "make some friends" which was literally the only way to reactivate the elements and defeat her.
2. DISCORD: Celestia mentions she and Luna are not able to use the elements anymore and mane six are the only ones who are able to. That explains why she could have not used them on Nightmare Moon's return. (Plus she helped by sending back her letters when Twilight Sparkle turned gray.)
3. CHRYSALIS: Celestia actually started to fight against her but got defeated because Cadance's and Shining Armor's love is too strong and the mane six were the next best options. Even tough it was Cadance and Shining Armor who defeated her in the end.

So far in these instances Celestia sent the mane six because there was no other option to defeat their enemies, simply because she and Luna cannot use the elements anymore.

4. SOMBRA: This is the only instance where a "test" is mentioned and she should be called out for putting an empire in danger for it. But that is still nothing compared to what Discord did.
5. TIREK: She sent Discord after him because she tought he would be the best option (he can sense magical imbalances). But when they got backstabbed she told Twilight Sparkle she should ran away as far as she can. It was Twilight Sparkle's own choice to face Tirek.
6. STARLIGHT GLIMMER AND COZY GLOW: She did not know about them. Moving on.
7. SUNSET SHIMMER: Just for bonus. They mention only one can go because a huge imbalance would happen between the two worlds. As for why choose Twilight Sparkle, it has been shown how the princesses are busy people, they cannot just leave their own world, and she is the smartest one who can somewhat navigate in new places.

So, what did she meant by "training program"? Either she meant it as "life always gives everyone lessons in the most ridiculous ways" or she plays 4D chess with the universe in order to get what she wants (or some similar crap like that).

7527344
Didn't think there were that many comparisons between her and Discord in such a manner, but yea, her methods weren't as bad. Still hate her for certain judgments she made though.

7527354
I am still mad at her for blocking Luna from helping too(such as during the Sombra thing) and the stupid "lets dump our magic on the chose one er I mean Twilight" plan with Tirek. That plan was so freaking flawed and I hated how Luna agreed to it too, almost as if she is unable to object to anything Celestia wants to do.

Ofcourse it doesn't make sense. That's just some bullshit the writers came up with last season in order to have Twilight Soopah Princess!!!

7527344
I lost count of how many threads I made in other platforms defending Princess Celestia until I noticed that the problem was that the writers didn't care about her anywhere near as much as fans cared about her. And I know that this is a very unpopular opinion, but it became even worse because once they started paying attention to her, they had not a single forethought about what they were doing.

Everything about alicorns is a mess, from the patchwork lore around the unicorns and the sun/moon to their non-existent origins all the way to the writers having no idea what to do with Celestia or what she's supposed to be doing.

What a great character, wasted.

7527787
Whoever wrote that line for her just clearly ignored continuity and what Princess Celestia really sent Twilight to Ponyville for in the first place! >:/

7528127
But like destiny and crap...!
That's what being Celestia's personal student was all about! (in season 3 when they thought the show was ending and they wanted a big, dumb finale)
Her cutiemark was on the tree of harmony! (suddenly invented in season 4 because Twilight wasn't special enough before)
Her friendship was so super-special-awesome it was the only thing that could save Equestria! (Friendship is Magic*)
She started the first and only school for friendship! (even though Celestia herself said friendship couldn't be taught in school first episode) *ahem* I mean, show is ending! (for real this time!) Needs more special!
Celestia and Luna retires and Twilight's the only one that can handle their job. Because destiny. (and crap...) The Edn!

_{* Some friendship is more magic than others!}

7528168
Yeah I mean, was it even Twilight's destiny at all though? :/

7528168
Luna and Celestia's cutie marks were on the tree too but apparently that means nothing since they lost their connection to the Elements.
The finale really rubbed it in that the sisters are NOTHING since they lost their connection to the Elements there.

7528168
Celestia never said anything about friendship being taught in schools.

Some friendship is more magic than others

To be fair, the student six was able to resurrect the Harmony Tree as a treehouse simply because their friendship.
Also, when they defeat the trio with the rainbow lazers Spike is also included in. I think that means any friendship is powerful in this universe, as of why Twilight Sparkle has her cutie mark on the tree, i dunno.

7528636
Huh... I appear to have been bamboozled! I could have sworn she said that at some point...

Well yeah. Every friendship is important. But if the world needs saving you need super-special-awesome friendship. What's up with that?

7528636
Iirc, Celestia said "Friendship can't be learned in books" to Twilight in the beginning of the show. As a counterpoint to Twilight wanting to read book all day instead of interacting with others.

Spike being included meant something had change so he is finally part of the Mane 6's bond truly.
Friendship is powerful but apparently not everyone and their grandma were included in the rainbow laser. So the 3 groups(Royal Sisters sadly not included for some dumb reason) have something that lets them manifest that "I automatically win because friendship" rainbows of doom.

7546085
Celestia never actually says that though. The closest thing to it is when she recommends Twilight "Stop reading those dusty old books" in response to Twilight warning her about Nightmare Moon, before telling her that there's more to life than studying and giving her the task to make friends in her letter. That's it.

7546180
Where the heck did that "Friendship can't be learned in books" line come form anyway?
I could have sworn it was said somewhere.

7547678
I don't think it came from anywhere within the show, I think it's a line people basically just invented. I think it's more so that some people felt that the concept of the "School of Friendship" contradicted some of the earlier ideas of the show. The original premiere does not have a line like this, no, but it does have the bit about there being more to life than just books, and Twilight needing to get out there in the world to experience life and make friends and all that. So, people talk about how they feel the school concept goes against the original idea, and one person with a somewhat faulty memory who hasn't watched the premiere in a while brings up this line that doesn't exist, then somebody else makes a meme of it or whatever, and since memory is fallible and this line that doesn't exist reaffirms a lot of people's feelings and opinions on something, it catches on.

Not the only instance of this I've seen actually. I've seen it happen in other fanbases, where somebody will bring up some line that was supposedly said at one point, and then it catches on and people are now discussing or criticizing a piece of dialogue that essentially doesn't exist. It's kind of funny.

7547686
Mandela effect.