My mother enjoyed Tetris, Mario and other 8bit classics back then. My father played Freecell trying to maintain as long win streak as possible (akin to what competetive young gamers typically do).

I bet my parents (including granddad who uses a laptop from time to time!) will be much better than me in some indirect financial management, something close to real-world “invest and get profit some day” concept. Or a court simulator. The things that younger gamers might not have patience for. But I doubt they will play it as those games won’t be appealing regardless of players’ age. Maybe a colourful turn based or slow and step-based puzzle with no more than 15-minute session will do the trick. Something you can easily leave to do you regular stuff yet eagerly come back.