Why is mastodon just so lonely and dry?

Don't expect to be entertained. Engage with people and they will engage with you.

Follow hashtags. That made the change for me. If you see interesting posts, follow the user and following hashtags makes you find the interesting users.

Try and follow hashtags, make sure your posts have a BUNCH of hashtags

Because in the mainstream platforms the people who share your interested are payed to make you feel like that. While in place like Mastodon, or here, you can feel the harsh reality.

Based on your replies maybe try the Roblox forum? More people your age there

also lemmy.ml is bad btw