All they talk about is only Equestria and not the other kingdoms. They think that only their land matters and not the other ones when that's not true. Why won’t anypony acknowledge the other kingdoms instead of just Equestria?

They need to actually care about the other kingdoms and creatures and not use or hurt them for their own benefit and only for their home without the other homes outside of Equestria.

Again, I know I've been bashing ponies, especially the Mane Six, for far too long and I know I'm going to get a lot of hate for this, but I'm just really stressed out about how selfish ponies are towards other creatures and I just want them to acknowledge them and their own kingdoms as well as treat them with genuine respect and empathy.

How would the Mane Six react to all this, though?

7631392
You have to understand the fact that unlike you, ponies don't have internet or the ability to travel around the whole planet in a few (dozen) hours. As far as we've seen, Equestria didn't seem to really communicate with other nations and it started changing only over the course of the show. Bashing ponies for not caring about other nations they are scarcely--if at all--familiar with is akin to bashing medieval folks for caring only for the village they've spent their whole life in.

7631392
I want to play this up further in future stories. But this is very much a sin of Wealthy Countries throughout human history. They think of themselves as the pinnacle of sapient achievement and they start declaring the rest around them as brutal savages deprived of the light of civilization.

7631401
This is also true. Even when we notice that ponies must at least have the tech to have the radio, in our own world nationalistic "my country first" thinking had hardly disappeared with it, and it took the televised reporting of the Vietnam War to start changing that general mindset. Even with the stories of the horrified veterans of both World Wars, and the Korean War speaking, and writing about their harsh and traumatizing experiences on the battlefield in literature.