Uber cannot afford to do any of the things you've listed because Uber cannot sustain the subsidies it is already giving out to its drivers. Moreover, Uber doesn't want its drivers to be educated about the true cost of operating a vehicle for Uber because if they realized how much it cost, most wouldn't do it.
The only one of your bullet points Uber has pursued is the last one -- they rope drivers into car leases in hopes that when they eventually ramp up the amount of money they collect from each fare their drivers will be locked into driving for Uber so they cannot leave.
I wonder how come Lyft can do these things and Uber can't. This is from 2 years ago: https://thehub.lyft.com/blog/2015/01/14/partners-ehealth-top... Every Uber driver I talk to in Seattle say that Lyft is way better in terms of pay/perks but they can't get enough rides because Uber simply has a larger user base.
Lyft is more expensive, which explains its better pay and its smaller ridership. I don't think this is sustainable because of what you've observed, which is that the smaller ridership pushes drivers away from the platform, making Lyft less appealing to even the people willing to pay (longer wait times, smaller chance of getting a carpool, etc).
I think it depends on the market. Lyft here (Philadelphia) is the same price as Uber just about, and they both run promotions all the time. Car availability is the same in my experience and most drivers seem to do both. Drivers seem to indicate that they get better subsidies to drive from Lyft.
I'll admit that lately I've been mostly taking Uber because it's cheaper than Lyft. So that probably explains it - Lyft simply doesn't cut prices as aggressively. (But I still check both because sometimes Lyft is cheaper).
The only one of your bullet points Uber has pursued is the last one -- they rope drivers into car leases in hopes that when they eventually ramp up the amount of money they collect from each fare their drivers will be locked into driving for Uber so they cannot leave.