Do taxis sell your data: when/where they picked you up and dropped you off? Do they sell your facial features for facial recognition? If not, then it is not the same!
I don't know - do you? Additionally, do you know they never will?
They're not collecting (AFAICT) facial information (though there is a camera in nearly all taxis, so it's possible) but it's hard to believe they aren't collecting route data even if it's just to place stands more efficiently to service commonly requested routes, at some point they might start selling that data... or they might be acquired and their acquirer might either sell off their data - or use their data internally for other purposes.
In the modern world we really have a lot of fuzziness when it comes to how usage data is treated. There are lots of UX people that want to know how people are using sites to make them better - but that same data can be resold for quite creepy purposes.
Existing taxis are ad platforms and not free, so this is still an improvement.