Most jobs work that way. A job has a set pay, and you can get fired or promoted. Tipping is unusual: A janitor doesnt get paid a different amount each paycheck because of how clean others feel it is this week. Cashiers who help you find things in the store don't make more that day.
Then it becomes a competition not in who can provide the best service to customers, but in who is able to look the best to the boss. If that means being fast and efficient, and not minding if you step on customers' toes, then the customer experience will falter. If that means talking about other employees' mistakes behind their back, then the workplace culture can become acidic.
Base pay has to be the same. You get merit based raised after that. How will they know who's better and who's worse at first? They won't that's why base pay is equal for everyone.
Some employees have so much experience or other skills that they can immediately ask for a higher base pay but it's not the average experience.
Tipping is ingrained in our culture so much that people will still feel obligated to. The best way to stop it is to take the tip line off the receipt entirely.
It's probably wishful thinking, but I could see this possibly curbing some of the entitlement people can get when using a tip-based service. And that makes for a better work environment.