I always pay the extra for a silver service car and never had a bad one. Unfortunately you have to be ready when you call and they can be 15-30mins in non-peak to 2-3 hours on a Friday night.
I always talk to the drivers when I am travelling by myself and many times I have had owners of the cars and you can normally pick it because the car is better quality and better maintained. The uber drivers are surprising earning well and I assumed it was because many forgot to take into account costs like interest and depreciation, but the ones I spoke to had and were very aware of all their costs.
There are a number of families that used to own a large portion of cabs, predominantly through extended family, trusts, super, companies etc. Everyone know the one that has a name like the brand name that races at Bathurst (and I don't mean Holden). Those players have always run Government policy and have tens of millions worth of licenses. Given the value of those would significantly fall (think they are $600k if you can get one when released by government and a lot more on the open market), you can understand why they lobbying so hard.