But why? I somewhat get the argument with waiters - they are paid shit wages, so somehow it became a cultural norm that customers have to subsidise waiters since their employers are too cheap to pay properly. Like, ok, I don't agree with it, but that's the system you build for yourself so that's the one you have to deal with.

But why taxi drivers? Why delivery drivers? Are those groups also poorly paid because they rely on tips? Why other social groups haven't adopted this? Are your electricians also charging $1 an hour of work and then expect that you leave a tip that saves them from poverty?