I'm something of the opposite. Very introverted, moved to a very extroverted American city (which one isn't) in my 20s for work and excitement. I pushed myself - dates, meetups, social stuff. Never cold approaches but now if you'd met me you'd think me an extrovert. I'm not, because people stress and exhaust me, but I hide it.
In my 20s and early 30s whenever I left the city sometimes on the weekends, I'd feel this FOMO like I'm missing something fun.
Something changed as I got older. I think around the pandemic. When I was in the city on a beautiful day, I felt this sad feeling like I should be in nature instead.
I eventually got a place in the country. Now that I'm not single, I couldn't give two craps about going out, meeting people, and I hate crowds and noise. There's no greater pleasure than sitting and listening to water sounds outside, reading and studying.
People are overrated, but you need them sometimes. Don't feel bad about being an introvert.
I suppose the equation is different for someone who is perpetually single. That one person makes a big difference.