Asklemmy

I recall reading somewhere making new friends as an adult takes 200 hours (it some arbitrary number) if time together in some social aspect. This requires some level of common interests as you speak of. I also noticed this factors in a couple of friends I have made. Those hours together though must be due to mutual interests and this the reason you build hours.

I see this in my personal life and those around me. As a child you often have many good friends. I have noticed the ones that survived into adulthood are those that took similar work paths. The ones that work in different fields tend not to be so close anymore. It also factors if you move away for work. Like I did. You simply don't see the people you had such strong ties to and that is difficult. You get busy and prioritization changes. Same if some have kids and others don't it do it at different points in their lives.

Work then becomes your next place to find people with common interests and skills. Generally this applies to jobs that are more career oriented and not the temporary mcjobs. The risk is that people job shop much more now so that friend of yours may move away. As stated joining social groups are also possible. But it takes effort and you need to be engaged to keep going. That can be difficult.