In Rust you can host your own server, and if you do that on your own local network with nobody else connected, then you have a very large world, with only like a couple of things that can kill you, and you can have a very fun, laid-back, relaxing, you know, builder, simulator, survival thing.

And also Skyrim. I have been trying to complete every single side quest and every single add-on side quest that I can, while basically not advancing the game at all. My current game is easily 40 hours in, and I only recently defeated the first dragon that you can kill as part of the main quest.