There are many cases where a somewhat expensive treatment saves a very expensive hospitalization.
For instance, a steroid inhaler for asthma costs about $200 a month, maybe you have two $200 specialist visits a year. So for $2800 a year (not covered by high-deductible insurance) you can probably be symptom free or you can take your chances and have an exacerbation and a $28,000 hospitalization (which insurance will pay some of after the deductible)
Docs hate them too.
With real insurance, you have maybe a $20 copay you pay at time of service and they know they are going to get paid by the insurance.
With fake insurance, they don't know what you are going to pay until months later when the insurance gets around to telling them. Then you get a bill that says you owe $291.44 for some unspecified service you got 6 to 18 months ago.
(They can't tell you what it was because that would violate your privacy)
Needless to say they have a big accounts receivable this way, many people don't pay or they pay late (e.g. a few months after getting a bill they don't understand as well as something that says "THIS IS NOT A BILL" they don't understand). This is not good for their finances or their state of mind.
In theory high-deductible plans might lead you to shop around between providers to get a better price but in practice nobody can or will tell you what things costs and it doesn't work.
It's a perfect example of the neoliberal mind at work.