FICS is still working, as far as I know. You will find more people playing on chess.com or lichess, but there are still some nice things going on there, e.g. their Teamleague.
Babas Chess

From time to time I still play there. Ratings are lower but stronger. Have had good times there. Offcoarse with modern alternatives it's a bit rusty.
now i tried it for a while, babas at fics. amazingly stable and before all, good piece of software, if we consider last update was more than 15 years ago. no way fics can compete with chess.com with all modern content which .com offers here, but when comes to pure playing of chess i found it still very active, no issues with getting paired and so on.
i am interested, if any one has experience, think it works on telnet principle, is it better for areas with slow connection than modern sites
i have some old version of babas chess, never actually used it seriously, is anyone using it, is this FICS still actual as playsite?