https://gs.statcounter.com/os-market-share#monthly-200901-202505
Both Linux and MacOS look fairly flat overall, with a few spikes for Mac. What did happen was iOS and especially Android went to the moon.
Most people had a PC for a bit of light office work, emails and storing pictures. All of that can be done on a phone and more besides. It's not great that a handful of Silicon Valley techbros are holding everyone's data to ransom, but that's what the masses are doing.