@ImIncrediblyOlD The clean boot is only for testing Sims 3, so you can revert it for regular use. However, I'd suggest not reverting just yet; there are a couple more tests I'd like you to run while in the clean boot.
First, I don't think we covered it, but are you playing in fullscreen or windowed mode, and does it make a difference to switch? Please do so at the Main Menu and quit to desktop before loading a save just to make sure you're getting the full effect.
Your dxdiag shows a few more generic Windows errors, and since DISM and sfc apparently didn't clear these up, I'd suggest running a repair install:
https://www.tenforums.com/tutorials/16397-repair-install-windows-10-place-upgrade.html
This shouldn't delete any of your data, but if you get to step 13 and are NOT asked to keep personal files and apps, back out and start over.
If this doesn't help either, I'd like to see the results of some hardware monitoring, still in a clean boot, to see whether any of your computer's components are behaving in an odd way. Please download hwinfo (it's free) from here:
https://www.hwinfo.com/download/
You don't need to install anything; just choose the Portable version, unzip it, and launch it from Downloads or wherever you like. If you do want the full installer, be sure to click the button for hwinfo itself, not for lansweeper.
Restart your computer, open hwinfo, choose Sensors Only, and click the button that's a sheet of paper with a + to start logging. Save the log file to your desktop for easy access. Wait five minutes, then open Sims 3 and play for at least 20 minutes. Don't alt-tab out of the game or run any other programs, aside from the EA App of course, while you're testing. When you're done, click the same button to stop the logging.
Please upload the log to the third-party filesharing site of your choice (Google Drive, Dropbox, etc.) and link it for me. Either leave it in .csv format or, if you're going to use OneDrive, create a .zip file, and don't open the log before uploading it, or else my log reader might not be able to interpret it.