But transit only solves your problem in cities like London. Some people - for some reason I’m still not entirely clear on - seem to like this. But other people - so far the majority - don’t. And for those, self-driving cars solve the transit problem. That’s valuable. And you only need to beat unit economics of taxis. So there is a significant margin to capture
Are you claiming that the majority doesn't live in cities? 80% of the US population lives in urban areas. Self driving cars contribute to the transit problem in those areas because it's even more traffic.
For the 'don't want to live in transit-dense cities like London' crowd, beating the economics of taxis may not be enough since that's not what you're competing with out in the suburbs.
On the other hand, the suburbs don't have much that is even comparable to city taxis in price or availability today, so maybe if it existed that price point would indeed do just as well away from cities too.
Self driving cars still create traffic jams and huge environment contamination No problem is solved.