Why do so many Lemmy instances use weird TLDs?

I get that some instances use the domain + TLD to make a word, like lemm.ee or to an extent, sh.itjust.works. But I've seen so many TLDs I had no idea existed, like .world, .zone, .social, and yes .works as well.

Is there any real reason for that? Trying to look cool or kinda underground-y? Cheaper and more varied domain options? Something actually kinda functional?

Interestingly, I started on vlemmy.net because I was a scared Reddit refugee and the .net TLD gave me comfort. Then it vanished a few days later without a trace. So here I am on lemmy.world