Is it just me or are the Princess useless?

I was thinking about each of the princess. Is it just me or are they useless. Celestia raises and lowers the sun Luna does the same with the moon. I have no idea what the hell Cadence does.

But I'm not going to talk about Twilight that would be a longer list.

When ever something happens (Discord returns, changelings invade, Tirek escapes, ect ) Twilight and the gang handle it.

I know Cadence helped with the Crystal empire with the shield spell to keep Sombra out but as far as I know that was it.

Let's stat with Celestia. When discord came and he was right there Celestia didn't even try to attack with her magic and she's said to be the strongest. But just stands there glaring at him while he fools around. During the changeling crap at first she didn't believe Twilight, gets her ass handed to her on a golden platter. Then we have the whole Crystal Empire crap all she did was have Twilight and the Mane 6 go over there where Shinning Armor and Cadence were trying to save the Empire. But she tells Twilight that she needed to do it alone like an idiot she is.

For Luna No one knew where she was during the invasion. She wanted to go to the Crystal Empire and help fight off Sombra But Celestia told her not to go. but besides that I don't remember what she does besides raise and lower the moon and help ponies with there dreams.

Cadence I have no idea where to start with her. First off what the Fuck does she actually do? She's the princess of love but what is love. Personally I think love is just a chemical compound inside our body that tells us to mate.

During the changeling invasion she played as princess damsel in distress until Twilight came along and got out of there BUT this was until Twilight got there and when she did Cadence was a mess. She looked like she hasn't bathed in days.

What are you guys thoughts about this