I found a server called Astralis and it is just a regular SMP.
It sounds like it is running on a small amount of RAM right now so it might get laggy or crash if it runs out.
The owner mentioned that if someone donates more memory then it could run better.
Astralis Simple Survival SMP Server
GG.MINEWIND.NET New Server IPFlok Scripting Engine for Spigot 1.21+
I found Flok and it is a lightweight scripting engine made for Paper and Spigot servers on 1.21 and up.
It is built so you can make custom mechanics and commands and event handlers with a natural easy to read syntax.
It also tries to be modern and safety focused so it avoids a bunch of overhead and helps prevent server freezes.WebsiteGG.MINEWIND.NET New Server IPSlug SMP Vanilla Survival With Voice Chat
I found Slug SMP and it is a fully vanilla survival server. It is pretty simple and it is just regular Minecraft with people trying to live and build.
It also has simple voice chat so you can talk while you play. The community is around ages 15 or 16 and they want people to be normal and not creepy.GG.MINEWIND.NET New Server IP