@gratsoy You're correct that the Sims 4 user folder is only generated the first time the game launches. Please undo any compatibility settings you still have enabled—Sims 4 should run fine in Windows 10, and a compatibility setting can make troubleshooting more complicated.
Try running both Origin and Sims 4 as an admin: right-click on the .exes or their shortcuts and select "Run as administrator." If you don't have a shortcut for TS4_x64.exe, you can find it in the game's program files; the default location for the .exe is
Program Files (x86)\Origin Games\The Sims 4\Game\Bin
If that doesn't help, just as an experiment, please try to launch the game with only one monitor connected; if the first doesn't work, shut down and swap it out for a different one. The game usually does handle multiple monitors without issues, as it should, but it's an easy enough test.
And out of curiosity, please move your Sims 3 folder out of Documents\Electronic Arts and onto your desktop, then launch that game. If the issue is a game creating a folder in Documents in the first place, you should see the problem with Sims 3 as well. You don't have to go past the launcher, since a new folder will be created by then, and you can trash the new folder and put the old one back afterwards.