c) Who Benefits?
Hopefully the staff, but unfort not always. There is no law for a restaurant to have to distribute these charges to staff. in fact, by law, service carge can be used as part of minimum wage payments. this is a real shame in my view. These service charges are then taxable, because the restaurant manages them.
If the staff pool together tips that are not part of a service charge, these are not taxable, and in theory they split as they see fit (and may or may not include the chefs/kps) but there is no guarantee that even these staff get all these tips, so the rule is ask - (do staff get tips?) if answer is no, consider tipping at all.
most decent and long term restaurants distribute all tips to their staff.
i don't believe in general all the service charges are distributed to staff.
best to ask.
you can even have the service charge removed and leave the"tip" in cash