You’re missing voice chat and video streaming

Add custom emojis and stickers to that.

Kind of baffles me that people still make chat apps without those.

Every chat product has these things?

...But one of these things is not like the others.

"Anyone can start a server" is only true when you're lying about what a "server" is. (Or redefining it to the point of usefulness.)

A Discord "server" is just a defined chat namespace. All the Discord chat "servers" live together on the same actual load-balanced VMs or whatever on the physical servers they run.

It's honestly the thing that's annoyed me most about Discord from the very beginning, long before they introduced the ads and the microtransactions and the mandatory doxxing.