In the USA the delivery drivers live off of the tips… it’s not just high school kids working a summer job. A lot of drivers are working a second job to support their families.
If you live in a major metro area in an apartment building, gain yourself a reputation for tipping decently and you won’t have to leave your apartment. Tip poorly and you will have to meet them down on the street.
It’s not something I voted for, this social contract existed long before I was here.
If I had a vote to abolish the tip system, I would. In the meantime I make sure to tip decently so that the person who gave me service can keep a roof over their head.