Absolutely, essential, oh yes.
As an example of intransigent work rules, one source pointed to a clause in the union contract that would prevent a busboy from being asked to perform other duties, such as unloading produce from a delivery truck.
The source also said the union — not management — would get to determine how many waiters work a particular shift.
Far better that the restaurant not exist than that a union not have such powers.
As has happened, the restaurant does not exist as the union demanded such powers.