Isn’t the gain that those folks can find another job that’s more useful?
What makes you think that if finding another job that they are capable of doing was so easy they wouldn't have already done so? Because they were waiting for some tech billionaire to throw them on the unemployment line?
Major structural employment changes don't happen overnight. This will take decades. AVs will decrease the demand for Uber drivers, but it doesn't mean they will all be out of a job overnight, just that incentives will slowly push workers towards other jobs.
I am neither a deliverator nor a cab driver, but I do enjoy driving. When the org I work for needs stuff transported, I often volunteer for the task. Driving in silence, or to music, or while listening to podcast; for work, for recreation, or merely to enjoy the drive; it's all good. Of course, I also live in an area close to mountains and while going toward the city nearby is hell due to traffic, going toward the mountains is blissful and beautiful.
It took insane levels of lobbying and political power of taxis to keep a hold on some of their biggest cities, and there are now few places where non-uber/lyft style systems are still in place.
If AI taxi's are cheaper and more convenient, there's no way they won't just completely replace human taxi drivers. Cruise and Waymo have huge incentives to undercut whatever Uber would try to do. So I don't share your optimism that it will happen slowly over decades. If this self-driving system is easily repeatable elsewhere, it will likely be fast and swift.