I worked hard physically as a dishwasher or warehouse worker, but had little mental stress.
I only lasted a few weeks as a waiter. Despite the much higher tips, dealing with bad customers was so stressful I couldn't handle it and it significantly affected my studying.
Whereas I never felt that tired when doing physical labor.
In Europe there is much less of a tipping culture, but at the end of the night all tips go in one big pot and then get divided amongst the staff.
It’s probably due to a difference in culture. The US was still very anti-socialism at the time. But the culture was definitely that you should keep the rewards of your own labor.
At smaller restaurants there was never any pooling at all.
Most servers I know prefer to keep their own.
I was a fine dining server for a couple years while in college before finding my first programming job. It taught me how to deal with pretty much any kind of person.