Phaewalker In case this is a system issue, I would suggest doing a repair install of Windows. This isn't a full reinstall but is as close as you can get without losing your data. Delete the same EA Desktop folder again (in Program Files\Electronic Arts, not in Documents; the folder in Documents is not relevant here) before you start. Here's how to do a repair install:
https://www.elevenforum.com/t/repair-install-windows-11-with-an-in-place-upgrade.418/
Once you've done this, download another fresh copy of the EA App installer (delete the ones you already have) and run it as an administrator again. Try to open the EA App by itself, not through launching Sims 4. The link2EA error should only happen when you're running an EA game through Steam, so if you're seeing that in a different context, that itself is odd. Make sure Steam isn't running in the background.