Just a random thought: Being a skilled player in Doom (And Quake + some other games) meant doing great in DM up until recent time, when speedrunners became the "pinnacle of skill" (Even doe it's just memorising level layout and passing it fast). Why did that happen?
The Doom speedrunning scene got started way back in the mid-1990s already and both good speedrunners and good deathmatchers were respected back then at least in the places I frequented decades ago. Of course none of the runners back then were trannies. COMPET-N was the Doom community's "official" repository of speedrun records. Eventually Adam Hegyi lost interest in maintaining it and things started to move to Troonworld and Youtube.
The best Doom speedrunners in those days were probably all good deathmatchers as well but not all the best deathmatchers were speedrunners. To give you some big names: ocelot, Johnsen, Sedlo, Yonatan Donner. All very good deathmatchers, all very good speedrunners. DevastatioN and JKist on the other hand always played deathmatch only and there were some very good European DM only players as well whose names I've forgotten.
In the current and previous decade Looper has been one of the best Doom speedrunners and is also a very very good deathmatch player, though practically nobody plays Doom deathmatch anymore anyway which is the answer to your question: these competitive "arena" shooters sadly just died off completely as a genre. Kids would rather play CS or Fortnite than duels. There's a tiny QuakeWorld (Quake 1) deathmatch scene still going on which even arranges international LAN parties occasionally but Doom has nothing.
If anything I (as an old DM only player) would say that speedrunning Doom requires more skill. You can get by in DM and score decently well (you'll still lose of course) against the best of the best if you simply have good aim and reactions even if your movement is lacking (mine always was no matter how much I played) and you keep sticking to corners, failing wallruns and item bumps, lack the manual dexterity to use SR50 optimally without cheating, etc. I'm not going to name any names here but due to the incredible power of the SSG, really really good (godlike) aim and reactions could even compensate for a very lacking intelligence extremely well, especially in maps like Dwango5 Map1 or Map7, Judas23_ or SSL2, all very popular in the duel scene when it existed.
The speedrunning grind always felt very boring to me compared to the thrill of deathmatching anyway but I'm not sure I could have been a speedrunner even if I wanted to. Dev and JKist probably could have managed it.
