1. In theory, a competitive marketplace should be able to cut costs and improve outcomes by incentivizing innovation and efficiency (of course, you also have to try to guard against incentivizing insurers to cut costs by reducing access to care). 2. Switching to a single-payer model would be incredibly disruptive to the economy. It would need to be done gradually to minimize the pain.
I actually work for a health insurer, but I've also been a big proponent of healthcare reform for quite some time (I see the ACA as a step in the right direction). I'm definitely not opposed to single-payer, but I don't think it would be a silver bullet, either.
Outside of theory, can you think of any example where this has actually happened in US health care?
The only cost cutting I can think of are notably lower payments to doctors, the insurers fighting every claim, and higher deductibles and co-insurance for the patients. So I guess that cut costs for the health insurer, but the providers and patients costs have gone up directly and dramatically.
Employers like the fact that I pay $200/month for my health insurance, they pay $1000/month. If I want a health insurance plan that improves outcomes and which costs $1500/month I have to come up with the $1500/month, not just the $300 difference. (the above numbers are all made up, but they are realistic)
I have long believed that we cannot solve the US health care problems without removing the incentives that force me to use my employers' policy like it or not.
In short, you don't see those examples in the US because the system is not competitive on outcomes, only costs. Since cost is the only thing they compete one insurers offer lower payments to doctors, fight every claim, add higher deductibles (which is a hidden cost on me) and co-insurance for the patients. These are innovative, not all are innovations that I would want my insurance company to come up with, but since I'm not a customer they don't care what innovations I want.