From someone that worked in the industry ~6 years ago, it's clearly going well for them - frankly, they're expanding and scaling way faster than I would have thought possible in 2019. They've got something like 6 cities running right now and what, 3-4 more announced?

Another thing to keep in mind is that rideshare revenue in the US is extremely geographically concentrated in urban cores. This is why every AV company was targeting SF as their first city (excepting Waymo, which did some stuff in PHX). 'Hyperfocused expansion' probably looks a lot closer to tackling new, novel areas in different metro areas rather than, say, expanding down in to San Jose and the central valley.

These things, they take time.

They've clearly hit (or projections confidently show they'll hit) a point where each car is profitable. I worked in the space for a while - platform upgrades (new cars, sensors, etc) are planned out years in advance and are pretty complex processes. But generally, each upgrade was a massive decrease in cost per car. (usually 50% cheaper or more). So also possible they want to wait for the next platform transition.