As well as what everyone else has said, it's completely fine, indeed natural and necessary to have shorter term, more superficial friendships as well as deeper, more long lasting ones. I have friends that are mainly centred around my hobbies, we rarely purely socialise without it being centred around the hobby in some way, most of the conversation is about the hobby and people come and go a bit from the group, if they move away or give up the hobby we probably wouldn't see them again. This is completely fine! It doesn't make any of us bad or superficial or ungenuine people, we enjoy spending being together and it still fulfills a social need that is beneficial to all.
Have you heard of the circles of intimacy theory, most people have 'friends' of lots of different levels, from very deep, very intimate, best friends type thing where you'd share absolutely anything with them and do anything for them (but you really only can have a few of this type of friend at most), to close friends you see often and share a lot with but maybe not quite to the same level, to more acquaintances, colleagues, context-specific like school and hobby friends. All are equally valid friendships just different in nature. And you have to recognise that while you have your circles, you yourself are in lots of other people's circles to different levels too...
Some friendships do transition over time, so someone who was originally more of a colleague or acquaintance or friend of a friend becomes more of a close friend which is lovely when it happens , but it's not like all the other friendships have then failed or been wasted because they haven't also made it into that circle/level. Perhaps more painfully through circumstance or whatever sometimes friendships go outwards a step where you were once super close with the person but have got more distant or had a falling out. But again I wouldn't see that as a failure or that you need to work on replacing them as such, it's all more fluid than that...