@rousuken Did that uninstall and reinstall process also include moving the Sims 4 folder out of Documents > Electronic Arts? You'd need to do it manually; this folder isn't usually deleted when the game itself is uninstalled. Please try this if you haven't already. Your saves and other content won't be available, but that's fine—the point is to see if you can play with no user content present at all.
If the game still won't open, please run a dxdiag and attach it to a post.
https://help.ea.com/en-us/help/pc/how-to-gather-dxdiag-information/