Got into Diamond Dynasty and building my card collection this year for the first time. Enjoyed that thoroughly without spending any money on it at all (which I know can be a problem for some folks) and without playing almost any online multiplayer modes. I was just building the collection for the sake of enjoying building the collection. Definitely activated the part of my brain that loved collecting IRL baseball cards my whole childhood.
I played it all summer long on Xbox while exercising and got into it enough I bought it for the Switch as well. I managed to put 200 hours into the game just according to the Xbox stats.