I know a bunch of people who don't make many new friends and this has many reasons.
People get families. They have time for other people after the kids are done. Depending on the time they got the kids this can take till they are mid 40.
People met a whole bunch of people till they got 30 and decided that they only need the 2-5 best who are left in the end.
People have a career that eats most of their time and they want to invest the rest of this time into their relationship and not general friendships.
In general I have the feeling many people are more focused after 30. Mostly on romantic relationships.
Most new people I added to my "friends" in the last 3 years were love interests. Since I'm polyamorous, this isn't much of an issue for me, but I can imagine this to be an issue for monogamous people. They get a partner and that's it. The people they meet after 30 who are willing to share much of their time are singles searching for a partner, so if you already got one, you're not of interest.
People get families. They have time for other people after the kids are done. Depending on the time they got the kids this can take till they are mid 40.
People met a whole bunch of people till they got 30 and decided that they only need the 2-5 best who are left in the end.
People have a career that eats most of their time and they want to invest the rest of this time into their relationship and not general friendships.
In general I have the feeling many people are more focused after 30. Mostly on romantic relationships.
Most new people I added to my "friends" in the last 3 years were love interests. Since I'm polyamorous, this isn't much of an issue for me, but I can imagine this to be an issue for monogamous people. They get a partner and that's it. The people they meet after 30 who are willing to share much of their time are singles searching for a partner, so if you already got one, you're not of interest.