You've never heard about capitalism? Zero labor cost means it's cheaper to have 100 taxis in your fleet when you would normally have 10.

If anything, I see it becoming the board game Othello to a degree, the big companies flood every inch of road with their cars instead of the other guys. I'd even see them using groups of their robo cars to create intentional traffic for their competitors, only to then communicate back to their own fleet where the only viable route through town is. This way it's like a tooth eat and if you want to get across town, you know it will take you 15 mins with Y brand and an hour plus with A brand.

Wake up and smell the death march called endless corporate growth.