typically in groups. You can see multiple friends at once

That helps but managing 3 friend groups at a time Is a huge commitment even for an extrovert. It might be feasible as a college or high-school kid but not as an adult with kids

It's possible, but you need to be very social. Basically you do group activities every few weeks, some people are friends but live further so you meet them rarely, and some friends either need to live very close to you or share some activities (kids clubs, maybe some fitness activity, maybe work, etc).

My sister has 10+ friends she actively maintains. I have 2 :)

I have like 4 close 4 mid and 4 far away friends and then probably another dozen work/activity friends but I don’t think I could maintain them all as close friends just too much upkeep.