Business owners are charging 5% service fees to outweigh labor. At what cost?

So it’s come to my attention that the owners of a local Seattle chain restaurant have added a 5% “service charge” to their transactions, which does not go to their staff. This is just a couple months after they introduced a 2.5% tax on all of their employees’ credit card tips, and also raised their menu prices even further. Is this standard? Employees are concerned that their tips are suffering for the sake of the owner’s imagined bottom line. We know at least 2 of their locations are more than profitable. It feels shady, but maybe others are doing it? Any info to shed light would be appreciated.