I can almost guarantee that if they don’t already, the robo-taxis will eventually start asking for tips.

This is already the case at self-checkout in some stores for example.

As long as the companies can get away with it, they will tack on any number of extra fees and charges even if those fees and charges really don’t make any sense.

Hell, even tipping people does not really make sense the way it works in some places. A person working for a company should receive enough pay from the company itself that they don’t have to actually rely on tips in order to make enough money to survive. Tips should be a nice extra that customers willingly add because of good service. Not a forced extra percentage that they have to pay on every transaction just so that the company can pay less to their employees.

That's just one tiny example out of sea of examples.

In a world where waymo works as a taxi, it also works to deliver a human-drivable rental car right to your door (and send it on to the next customer when you're done with it).

So now the short term car rental user experience should be dramatically better, even if the robotaxi isn't appropriate for all the tasks.

This or an equivalent will arrive to a robo taxi near you when the service inevitably gets enshittified to hell and back.

Ads, trips shared with other humans, pay extra for heated seats, etc.