Issue with RS2Beta is the lack of maps. Servers have been released for 194 rs2beta and also 289 in the past. There was a 289 project open source in the projects section.
The thing is, there really isnt a ton of content. I mean, itd be kinda cool to go back with fighting kq with garbage gear, but even that wasnt in beta.
Slayer had added a bunch of items/content to the game. Also lot of content like ancients/barrows etc are so ingrained with the players I dont think a server lacking that would take off.
Edit: Here is an Apollo 289 also that has some protocol/a somewhat fixed cache. Pretty sure some are still bugged.
https://www.rune-server.ee/runescape...ry-2005-a.html