Aren't there a bajillion online multiplayer FPS games out there spanning multiple decades?

A little while ago I set up a fan-patched version of MoH:AA (2002), and there were still enough people playing that I had a choice of servers to join at any time. There was less choice than there was in 02-03 of course, but it didn't feel much different to how it felt playing it back in the day (in fact it was better cuz there were less haxx0rz shooting you through the floor)