I think when people say "auto accept" they mean that the system is quick to accept at any touch of the screen in the lower half.
Here you are, minding your own business, maybe typing a text, and the ping comes in. Before you hear the sound, it recognized your finger or thumb on the screen and accepted the ride.
I call it premature acceptance. And I almost always cancel or ignore the request, knowing that it will piss the customer off. This then costs the company a customer, sometimes. If they want to play psychological mind control games with me, thats fine, I can play right back.
Uber did not do this until recently. Their new app does it all the time now.
Lyft has been doing this for quite some time. They could fix it, but so many new drivers feel the pressure to complete the ride that they "accepted" that they will not change.
And no, you cannot sue. You agreed to the TOS, which includes using THEIR app, the way THEY designed it. Take it or leave it. Don't like it, then quit. That is their attitude. You have a higher chance of success suing Pepsi for giving you diabetes.
As far as money goes.... every time they lose a class action lawsuit, it costs them between 10 and 300 million (ballparking, obviously). How many do they lose per year, 1? 2? 3? Their most recent earnings release they said they currently have over 7 BILLION cash in the bank. That will increase in the next 9 months when they IPO. They can afford to deal with your class action lawsuit, which will get sent to arbitration anyways.
It sucks, but that's how it is. Don't hate the messenger.