I live in a large US city (the District of Columbia) with both a conventional regulated taxi service and Uber/Lyft.
Let me look at your points one at a time:
--Insurance: The auto insurance market is developing insurance policies for these sorts of drivers. In any case, I imagine that the average Uber driver is a better driver than I am (it's her job, and just a means of transport for me); when I accept a ride from a driver, I know she might wreck and hurt me. If she does, her personal liability insurance (which she's required by law to carry, like any driver) will cover some of the cost, and my medical insurance will cover the rest.
--Technical inspections: Uber drivers' cars have to be no more than two years old. Technical inspections are required for *all* cars here.
--Reliable costs: Reliable costs mean unreliable service. Once there was an unexpected snowstorm and my mother needed a ride to the airport. There were no city taxicabs anywhere, but we could get her a ride on Uber, albeit for double the cost. Price signals let buyers and sellers communicate supply and demand, and are a good thing.
--Proper filing of taxes: Uber drivers have to report revenue earned from their work to the American tax authorities, just like the fellow selling fruit out of a truck by the side of the road. Nobody wants to shut down fruit stands because they might cheat on their taxes.
--Drivers can indeed form a labor union if they want -- they can get together and collectively bargain with Uber through a representative. They haven't yet, but they could if they wanted.
--Many employees in the US don't get health insurance, Social Security payments, or pensions. As independent contractors, the drivers are responsible for taking care of themselves; many have second jobs that do have these perks, and all of them know that there's no health insurance going in. It's no different than someone who owns a small business: if they want health insurance they can buy it separately, and if they want a pension or social insurance they can save money.