It's been my personal experience that it's not always straightforward to make friendships in adulthood. I'm not really sure the reason why, tbh I have wondered the same things you are wondering now at times.

It doesn't sound to me like you did anything wrong. Perhaps there were just no 'sparks' (for want of better word), idk, IMO friendships can be every bit as tricky as romantic relationships in their own way.

Sorry you are feeling hurt.