As more businesses turn to point-of-sale kiosks for tipping, there's no proof the money goes to workers.
www.cbsnews.com
This is an article about tipping self service machines, not something I have personally come across but certainly has been plenty of stories about it.
The minimum wage thing is a bit of a red herring, I worked a tipped position briefly and the money was not in the wage but the tips. For example in your average Restaurant you will probably find that the best paid employee is the top Server. Going to earn a lot more than the Chef.
It used to be of course that many tips were cash, you were supposed to declare how much cash you had received for payroll/tax purposes, well declare something so it was not too obvious. Some people still leave cash but that is less and less common.
It used to be you tipped $1 a beer, now 20% is probably the norm. 15 to 20% in a Restaurant, I do not do Starbucks etc, trying to think when else, for me that is probably it. It is interesting to see the suggested tip options, usually it is 15 to 25% range but I have seen some start and finish higher but I think they give you the option of a custom tip, might be difficult to find it. When I see stupid levels I go down one level on what I would otherwise have done.
There have been stories about places who have gone to a non tipping mode, never seems to work for whatever reason and my favourite:
Handsome Her, a vegan café in Melbourne Australia, sparked global debate in 2017 when it announced it would offer women priority seating and charge men an 18 per cent premium to “reflect the gender pay gap”. After two years of trading, the café announced it would be closing its doors for good on April 28.