Removing games from player inventory is very rare; I’ve only seen it happen when malware is uploaded to Steam as a game.
I have a few games that can’t be played anymore, like Super Bomberman R Online and The Crew. I still can download their files from Steam; but I can’t play them.
But now I’m curious too, what could’ve happened that got that game removed from the people who bought the game
Even when that agreement expires (see blur as a race game example), the game typically isn’t removed from libraries.
As for your game I think archive.org has a copy listed ( https://archive.org/details/race-driver-grid_202112 ), it says it’s a GOG copy so it shouldn’t give any issues, does it give any? (Do not click the spam comments, check the download options and pick either zip or torrent)