A hassle? Again, I seriously doubt you've been to an ambulatory for anything worse than the flu.

Having to wait until things become serious has long term negative effects on your health. (e.g. delaying getting checked out for a persistent cough until you have pneumonia)

Further hospitals are not ignorant of the issue of people without money or insurance. Unless you were delivered by an ambulance, they will run through your entire financial situation and demand up-front payment. They will bill you and they will send bill collectors. And they will happily bill you far more than what any healthcare provider on the planet pays for those services, let alone what they'll see after giving bill collectors their cut.

And they will happily provide inscrutable bills, separated between each legally-distinct part of their operation. (A bill from the ER, a bill from the doctor, a bill from the lab, a bill from the x-ray service). These bills will show up months apart and months after you were seen. And you'll have absolutely no clue how many to expect.

Unless you spend hours with their payment departments trying to get estimates. (Good luck if you were seen after normal business hours.) And even after you spend hours getting these estimates and negotiating fees and payment schedules, these have absolutely no bearing on what you'll ultimately be billed. Nor will the various legally-distinct parts of the ER necessarily be clued in or included in your discussions.

And ERs and ambulatory care centers will turn you away if you can't pay, up until you are delivered by an ambulance (or in that kind of state).

And, yes, HMOs and the like are a wild improvement over that. You may have crappy care with piles of restrictions, but the starting point for your fees will be far lower than if you were on your own. And the plans' coverage will spare you from hospitals pushing expensive services when cheaper ones will do. And it will spare you from other hospital shenanigans, like the $40 over-the-counter aspirin. The $200 saline when a gatorade will do, the procedures that were never performed, the ambulance rides you never took, etc.

And you will receive 1 bill. And have 1 company to deal with to pay it. And whatever you work out with that company will be binding on the entire event. There will be no surprise follow-up bills from parts of the hospital that you didn't even know you received a service from. (And you legitimately may not have)

My parents were self-employed when I was growing up. I've had health coverage on and off over the years. I know of what I speak. Not from a one-off event in a relatively healthy youth. But from 30 years of experience seeing an entire family having to deal with health care. And let me assure you, that the billing shenanigans are the rule. Fee-for-service has warped the practice of medicine and the uninsured feel the pain disproportionately.

Also: what do you think insurance company healthcare is, if not run on a budget? It all is. Even your hypothetical 'the best i can afford' care. Up until you reach a budget of tens of millions of dollars.

And you'll always be able to get better care if you pay more. That's true if you're uninsured, if you bought your own care, if your employer pays your coverage, or if you get coverage from your government. The UK has higher levels of care available. As does Canada. As does Australia.

Why do you assume that correcting the problems in our healthcare system and providing everyone with a sane base level of care remove any incentive to get better care? Are you suggesting that for-profit healthcare will evaporate in a single payer system in America, despite that having never happened in any other country with a single-payer system?