The sims 4 won't open.

Lilliputtinen  This should absolutely be solvable.  First though, if you've possibly deleted some files or folders the game might need, please run a repair (EA App > Sims 4 > Manage > Repair) before trying to play again.  This won't put back the Electronic Arts folder but should restore any missing program files.

The Electronic Arts folder, with the Sims 4 user folder inside, is only generated when the game loads successfully for the first time, or the first time since the folder was removed.  The fact that you're not seeing it now is a symptom of the game failing to load rather than the cause.

It would also be useful to know where this folder should be located, in case this is a permissions issue.  Sims 4 tries to use the computer's Documents directory, as designated by Windows, so I'd like to know what Windows says is the directory.  To find out, search in Windows for Command Prompt, open it, and copy and paste this command:

reg query "HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders" /v "Personal"

Then post the result.