One of the best things about Unreal Tournament are the player created maps mods models and mutators which at one point spawned several of review websites to help players find the best new content, forums on development, and filesharing sites. Creating that content got a number of people into programing and video game design. The result was so much amazing free content that I've played on and off for several decades and still have deathmatch and CTF maps on disk I haven't gotten to.
The game industry supported all of that in a way that they never will again. If UT was made today they'd be suing people for creating "cheats" for their game and they'd insist that you have to buy maps and mods as DLC