Is it safe to delete Sims 4 programme files folder after uninstalling?

@Grimghost13089  Yes, you can delete these files.  I've seen Origin install a second set of the game's program files, not the entire thing but a substantial portion, on a computer where I changed the default install location for Origin games.  (Others have reported this as well.)  If you did the same, perhaps Origin reacted the same way.

Regardless, these are program files and you can delete them.  You'll get back all the game data you need if and when you reinstall.