Maybe. But managers get paid shit. Most managers are lucky to get more than $25/hr. With even keeping 10% tips (bad tips minus tipouts), servers only need to sell $250 in sales per hour to make that without any base pay.

Servers would make much less money if "the owners paid them". It would become a job someone would only do in absolute desperation rather than by choice. Max pay most places (if tips were eliminated) would be $12/hr.

Tips are just commission set by the customer.