A lot of senior citizens love playing card games on computers. I prefer backgammon myself, although I'm not a senior citizen.
I am 70 years old, and the only reason I am not currently playing video games is because I play them on my PC computer, and I don't have a gaming console. PC games are few and far between now, and the last one I wanted to play will not run on my PC because it is not powerful enough. I wanted to play doom 4 but I can't and I am not prepared to upgrade my computer for just one game. If other new games for the PC are released I might upgrade then. But it seems PC games are a dying art.
Yeah, you have to update if you want modern games.
I'm more into classic 8-bit stuff myself. There was an excellent remake of the classic (Commodore 64) 8-bit Paradroid for PC (free), I would definitely recommend that one if you are into classic stuff, but be aware that there was a second PC remake of that game which was not as good.
I also love stuff like Tetris, Pinball and similar games.