I tried playing every WWE game since 2k22 again. I do this every 4 to 6 months to see if they work. I even deleted almost all created and downloaded content to avoid constant crashes. I played every game except 26, and they all crashed within an hour. So it's never the created content slowing you down, it's just a terrible game. You can't explore menus, view superstars to edit, and sometimes can't even get far into Universe Mode without a crash.
I'm beginning to think that whatever updates they do, they make your game buggy. Because I remember every game playing well until like the second update. I think that maybe this is on purpose, so that you're pushed towards spending on the next game. It's why they give you half of the content that you want, and then give you it in full during the next game.
I don't know, it's just a theory. I'm sure this'll get disliked to hell like every post I make.