Are there some good online shooters out there whose network lobbies are not dead ?
Are there some I missed ?
What do we play today ? Doom online, quake live or that abandoned UT 2019 alpha thing ?

Last online action I enjoyed was max payne 3 online and gta V deathmatches, although the're no old school shooters but served me a good time.

I never layed hand on any COD game, because I never felt attracted to the game's overall setting, they way of its marketing and the intuition that it must have a player base I dont like. But it gets more attractive the more desperate I become, so help me ;)

You should try Quake Champions. The number of players isn't great, but it's still not a problem to find a game even during weekdays.

It's definitely worth checking out. The game is still supported by Bethesda. There are still even official tournaments.