The ranking stuff is all just trying to capitalize on esports, which is weird because the vast majority will never be that good anyway. It’s a big part of what makes various communities toxic rather than fun. Playing a game where winning doesn’t really matter vs. people dreaming of being paid to play video games. It’s turning something that was a fun sort of power fantasy to kill time in, into something misconstrued as a profession. (In the same way an average guy might believe Himself of the quality to play DB for the colts, without the ability to discern the obvious physical differences between himself and a guy who is 6’5”, can bench 450 pounds and run 30 miles an hour. It actively creates these sort of mean/ delusional types who are harder to laugh off than they would be in another arena.
I'm not familiar enough with the history as I was pretty young when doom came out. Hacking on Doom and Marathon mods was my first experience with programming of any sort.
Good: You can finally play the game as it was meant to be. You could not find a decent server in CS 1.6 where you could play 5v5. You need additional sites/communities/XYZ (e.g. ESL) to play it. Similar with TF2 in the early days. Also, bad admins can't kick you anymore because you use a weapon they don't like. I could forgive such behaviour, but as games introduced some leveling or other statistic stuff, I can't. Just make your server unranked (nobody playing on these).
Bad: No sense of community. Like you said, you need friends first. Reports for cheating are useless, as you won't see that person again anyway.