@MadWattson Are you saying that you can still play Sims 4 after Revo supposedly removed it, or that you can't play but the EA App still thinks the game is installed, or something else? If you can't play but the App says the game is installed, I'd uninstall the App with Revo as well, then restart your computer and reinstall.
Please also find the location where the EA App says Sims 4 is installed, if it does in fact say that. Open your game library and click Sims 4 > Manage > View properties, and you'll see the location there. If the game is present in that location, close the EA App, kill the EABackgroundService in the Task Manager, and delete this folder. Then use Piriform's CCleaner (the free version is fine) to remove any Sims 4-associated registry entries.
Restart your computer again and reinstall the game, this time into a new folder you create for this specific purpose. The folder should be on the root level of the drive of your choice, for example C:\Games is fine, but not C:\Program Files\Games.
If none of this helps, please let me know what you're seeing: whether the App says Sims 4 is installed, where it's supposedly installed, what happens when you try to do the above steps, etc.