It really depends on what type of server you play on as well as what your definition of 'friends' is.
For big servers like Hypixel, you don't really get the time to talk to people. You're with the same people for about, 10 minutes maybe, before you move on to the next minigame, and 10 minutes generally isn't a lot of time to make friends.
With moderately big servers like Shotbow, their Annihilation gamemode generally lasts about an hour. You're in the same server with people for about an hour, and because the gamemode supports up to 120 people per game there's a big chance you'll meet the same people multiple times in a day and/or week.
For small servers, like for example private Patreon servers, It's really easy to make friends. I've been part of one such server and basically, everybody knew one another. I've been in discord calls that lasted up to 10 hours because we were having so much fun just playing the default game.
