You're ignoring the part that it should not be the customers burden. Sales and marketing people have high ceilings too, I can respect the hustle, BUT they don't get tips. They get a normal wage/salary and their company is on the hook for providing bonuses/commissions. It's not consumers "working against" the workers, it never should have been positioned that way in the first place. If business owners want to incentivize hustle, they should do it on their own dime.

It's a grey pattern to offer your product at 1 rate but implicitly you impose an additional 12-20% . Just pay them more, and charge more for the product, the end result is the same from the consumer. If the workers are no longer satisfied, there are other sales and marketing jobs that offer real salaries plus bonuses/commissions as mentioned above.