It says on the receipt that they use the service charge to post a higher wage so if that is true then it does (indirectly) go to the staff. Like you say though - there’s no guarantee that it all goes to the staff.

This would reduce tipping a lot, so if the staff weren’t being paid well to begin with I don’t see how they’d continue working there.

That’s how I interpreted the contents of the receipt, that’s all I can tell you.