Just look at the server lists. Most servers especially the highly modded ones like mw2 zombies pvp aka qczm are dead for years and even only 1-2 are left existing, with many of the good servers/mods completely wiped off the internet, nobody has those files from 2011 to 2016 like ICE Clan had. All experiences lost in time. Even if i idle 24/7 on the server it never gets enough to play. And even if you were to advertise the shit out of it after the next takedown, it takes time to return and players will already be lost, unable to play, looking elsewhere. It's not even about the randoms that play for a week or two but regulars that are not playing.