jonsamava Do you have Smart App Control enabled in Windows? That did block Sims 4 for a while, although the problem seems to have abated for the most part. Still, it could certainly hit Sims 3 with a Windows update. I'm not suggesting you necessarily disable it if you have another use; this would be more about gathering information.
I haven't seen enough to say that Windows in general doesn't run Sims 3 anymore, so the problem is not going to the overall OS, just some feature. If you use Windows Defender, please check it, including Controlled Folder Access if it's enabled, for any recent actions involving Sims 3 as well.
If neither of these is the issue, please create a new admin Windows account and try playing there. Make it local, as in, don't link it to your Microsoft account or any email address (so there's no OneDrive tie-in from the beginning—no account or email means nothing to link to). You'll be able to at least try to launch the game without reinstalling anything.