SIMS 4 crashing/ unplayable

ancko  Are you getting BlueScreens when playing Sims 4, or is it only that the game crashes or the computer freezes?  I ask because your dxdiag lists three BSODs but doesn't provide any context (which is normal).  Even if these aren't directly Sims 4-related, they could be contributing to the problem.

Your dxdiag also lists one crash of a graphics driver, so it's worth doing a clean uninstall of the Nvidia driver, and perhaps installing a slightly older version in case something about this one is a problem.  Here's how to do a clean uninstall:

https://crinrict.com/blog/2019/02/clean-re-install-of-graphics-drivers-with-display-driver-uninstaller-ddu.html

You can find older drivers here:

https://www.nvidia.com/en-us/geforce/drivers/

Make sure to select Game Ready Driver under Download Type so your results go back farther.  I'd try the driver from December 5, and if that doesn't help, the one from January 30.  You can simply install the newer driver as normal, no need to DDU—that's only required when you remove a newer driver to install an older one, or when a standard update doesn't resolve a driver-related issue.

If this doesn't help, I'd suggest running the game on the Intel iGPU as a test.  This is obviously not a good solution, but it would narrow down the source of the issue.  You can select the iGPU for TS4_x64 under Windows Settings > System > Display > Graphics as well as in the Nvidia Control Panel, under Manage 3D Settings > Program Settings > ts4_x64.  Let me know what you find.