I had honestly forgotten about reason #1 as I haven't heard anyone mentioning the service when leaving a tip in decades. IMO that's dying boomer behavior. Everyone understands that tipped workers are universally underpaid, and either tip generously in solidarity (if they are normal or vaguely left wing/liberal) or tip the minimum they can get away with socially or legally (if they misanthropes or right wingers). The tip isn't an optional part of the bill -- withholding it is deliberately underpaying vulnerable workers who probably have little control over their conditions of work (and therefore the level of service) anyway, so it doesn't even work as an incentive. If you don't like this, cook your own food.

When service work is strongly organized and represented we can start talking about changing tipping culture.