As long as they're breakeven keep it running? I guess that also takes employees and not many are interested in just maintaining a website

I never heard of the site until now, how hard would it be to convert it to static?

Flash games are static content (except for high scores). A Flash game is just a SWF file, typically a couple MB (or KB!).

If you'd like to experience the games that were available on Miniclip back in the day, your best bet is FlashPoint, a big offline archive of Flash games (ships with integrated FlashPlayer and a nice UI to search for games).

https://bluemaxima.org/flashpoint/