The medallion system helps create gypsy cabs. If starting a legal and licensed taxi service just required filing the same type of paperwork as any other similar company, and becoming a regulated taxi driver was more like becoming a truck driver you'd probably see a lot less gypsy cabs.
In NYC, that's exactly how it works, just pass a simple test and do some paperwork, and you can drive a cab. Medallions only restrict cabs that are permitted to take street hails in lower manhattan -- as long as you don't do that, there's no limitation on numbers of cars.
Uber and related apps are a bit overrated in terms of their "innovation."
You see, Uber-like "radio dispatch" services have existed in the NYC area for decades, but they used regular phone voice calls, not apps, which was slightly less convenient, I guess, but barely. It was not really qualitatively different IMHO (you waited about the same amount of time, and have about the same amount of certainty about the fare and whether they'll show up.). In fact, it could arguably be easier, as you didn't have to sign up for an account, download an app, set up payment method ahead of time, you just dialed a phone number
The only real innovation ridesharing apps have brought IMHO, are carpooling options like UberPOOL, Via, etc. This was not as practical to do before apps that could automate the dispatching and matching involved
I suspect that you have never actually used a phone-dispatch car service in NYC. You have no visibility into their ETA. Call back and ask... the answer is always the same "5 minutes".
I've used it tons of times. I grew up around here. You're right, you don't have much visibility into the ETA. I THOUGHT that was an advantage of Uber, but it's not -- I've sometimes called Uber and they blatantly lie, bait-and-switching about ETAs (eg, 3 min before I click, then it becomes 12min). Also, dealing with the ETA is easy. Wait 6 minutes, if they don't show up, call a different car service. The problem will take car of itself.
The "best" part about Uber is they penalize you for waiting too long to cancel your Uber so if the guy takes three times as long as promised and you cancel then you are charged the cancelation fee.
Yep. San Francisco has been utterly inundated. The last estimate I saw was ~48,000 more vehicles from the app services. Most of those are additional, because they are coming in to the city to drive (e.g., the drivers don't live here).
Important to keep in mind that that is not only a lot of cars for SF, but also that they aren't just driving a bit and parking. They're driving and driving (and driving and driving), when they're not blocking traffic picking up or dropping off.
In urban areas there are good reasons for restrictions on numbers.