They all look like Ponzi schemes at the moment.
Public transport exist, and for people that actually need a car on a daily basis, cars exist.
Taxis are luxury service and not subsidized ( as that word is defined in the dictionary) by money offsets. We can derail this into whether medallions/insurance regulation should be there, but the hard cold argument here is : Money. Lots and lots of money.
Uber/luft are subsidized by hard cash just to exist.
I drive, so from the outside, this looks as if somebody was subsidizing Android watches, because they'll overtake real watches.
It's a business gamble, but many are mistakenly taking it as a fact.
So, correspondingly, expect either prices to keep rising on Uber/luft/etc, or them to go out of business.
Is there a particular reason you are restricting scope to only the US? Taxis and "ride sharing" organizations are an international phenomenon: I'd say the majority of jurisdictions do not have medallions. And the upstream point remains - most taxis can now be hailed via mobile apps.
Oh I'm sure we can make money with all these users. I mean there are so many of them. We just have to wait until the incumbent starts collapsing, and burn money until we start collapsing, and someone else figures all those users must be worth something, so they start burning money, and...