I think this one is depend on which platform. PC or Consoles.
I was a PC guys and I found many games that I could play with endlessly.
Games that has no ending; such as Sim City 4 or City Skylines. You can build as many city as you want. Civilzations games also has ton of replayability, I used to play CV 5 for hundred of hours in my steam account. But as for the console, I personally hard to find a game that can be played for a long time.
I am playing AC Odyssey right now, fun for a couple hours in its massive open world. But grinding all the time and do everything over and over again, it just getting bored if you are not in the mood.