FPS++ is a client-side (won't support server-side) or modpack comprised of the best performance mods (e.g. Sodium, Starlight and Lithium, along with many more) and libraries/API mods (e.g. Fabric API, ...
The Minecraft modding community has grown exponentially over the last 15 years, with loads of mods having unique feature sets competing against each other. Not all of these mods are intercompatible, ...
Although, we aren't quite at the 1.20.x stage yet. Right now, CheatBreakerX is in development. The versions being currently worked on include 1.8.9, 1.9.4, 1.10.2, 1.11.2, 1.12.2 and 1.14.4 - though ...