I quite often feel americans show a lot of interest in new people they meet. If I tell something about myself usually they think its ‘amazing’ or ‘wonderful’, ask questions, not often steer the conversation to themselves. I think thats a quite nice cultural thing you have.

I agree this is nowadays hard to find. old school forums on specific topics (tech, games, music) tend to catch this. Gaming groups (guilds, multiplayer based games, modding communities) I have had great interactions on.

Anything that is a bit more ‘specific’ or focused around a hobby tends to work good for opening discussions. Its a shame a lot is focused on reddit but not all is so don’t lose hope!