Tipping is an evil practice and we should all boycott it.
First, it puts the economic risks of running a business on the low paid employee rather than the wealthy owner. For example, if you own a restaurant, you keep your restaurant open from 12pm-10pm. You know most of the customers come between 7pm and 10pm but you can't just open for 3 hours. You hire staff and pay them $3.50 an hour knowing there will be several hours where they will not get any tips. New waiters know that they will often get the shifts where no customers come but they still earn $3.50 an hour.
Second, if your restaurant is terrible, if the economy is down, if you decide to open in a bad location, no customers come and the owner has lost nothing but $3.50 an hour. If the restaurant is understaffed and customers tip badly, they also don't earn very much. Some weeks a waiter might earn a lot, some a little - but their rent and other expenses stay the same.
Third, many waiters will say, I like to get tips because I earn more than I would if I was only earning minimum wage. What they are missing is that restaurants will not be able to pay minimum wage - they will have to pay above minimum wage (like McDonald's sometimes does when they really need staff). And they will be better able to predict their earnings.
https://time.com/5404475/history-tipping-american-restaurants-civil-war/