xman_iceman After the reinstall, can you get the Sims 3 launcher to show up? If so, you now need the Alder Lake patch or another workaround, applied to TS3W.exe, with the W. Disc installs still have this issue because of course they didn't get the patch to the EA App version.
When creating a new Windows account, there's an option that says "I don't have this person's info" or similar, actually two of them, in small print below the field where it prompts you to enter an email address. Or at least that was the case when I last created a new account about two months ago.
However, the important point with the local account is to keep Documents away from OneDrive, as simply removing OneDrive doesn't necessarily move Documents back to the default location. What you can do here is confirm that Documents is NOT inside the OneDrive folder. In the new account, have a look at the registry entry that governs the location of Documents and make sure it's the default location:
%UserProfile%\Documents
rather than anything else. Here's how (and how to manually change it if necessary):
https://support.microsoft.com/en-us/topic/operation-to-change-a-personal-folder-location-fails-in-windows-ffb95139-6dbb-821d-27ec-62c9aaccd720
As for why there are no errors in the Reliability Monitor, do you use some kind of cleaner app that deletes temp files? If so, please disable it for now, as it may be deleting the crash logs the RM would otherwise translate into usable errors.