I found a private Minecraft server that is built around a player collar mod where people can be leashed. It is pretty weird on purpose and the whole point is to have more players around so it feels more fun.
They said there is a deficit of pet owners right now so you can join even if you do not want to wear a collar. To get in you have to apply in their Discord so you can be whitelisted.
They also do backups one to two times a week so griefing is a waste of time here.
Leashable Collar Mod Whitelist Server
GG.MINEWIND.NET New Server IPBuild Your Own Modded SMP
I found a modded Minecraft server that is inspired by a content style SMP but it is not scripted so it feels more real.
You can publish your own mods for the server which makes it sound like everyone can help shape what gets played.
To join you have to fill out an application form and they also say do not put any personal info in it.GG.MINEWIND.NET New Server IP