@HomieWonKenobi If you use a third-party antivirus, please set exceptions for TS4_x64.exe and EADesktop.exe. And look through the antivirus notifications to see if it's blocked anything Sims 4- or EA-related recently. Please also run the EA App itself as an admin: right-click the desktop shortcut and select "Run as administrator."
If that doesn't help, try playing in a clean boot:
https://support.microsoft.com/en-us/topic/how-to-perform-a-clean-boot-in-windows-da2f9573-6eec-00ad-2f8a-a97a1807f3dd
The one service to leave enabled is the EABackgroundService, which the EA App needs in order to launch. Disable the rest as described.
When you reboot, go through the Task Manager's background processes list shutting down anything that doesn't absolutely need to be running, for example a utility like MSI Afterburner might still be active. If you accidentally kill the wrong process and it doesn't restart on its own, just reboot your computer again.
If you still can't play, please look for any related errors in the Reliability Monitor. Hit Windows key-R and enter "perfmon /rel" without quotes, and you'll see a chart of errors and updates with a column for each day. Today is on the right.
Look for an error that happened at exactly the time of your most recent attempt to launch Sims 3, specifically in the clean boot. If you find one, double-click it to see more details, then copy that info and paste it into a reply here. If you don't see a new error, check back in an hour or so—the Reliability Monitor doesn't always update right away.
If you can't find any related errors, that's helpful information too.