The distortions caused by ACA will be papers in 20 years. It is so much worse than single payer or the previous corporatist insurance oligopoly.
The ACA allowed me to get insurance for the first time since I'd left home several years before. I knew lots of other freelancers at the time who were in the same boat.
Of course in the following years, insurers found plenty of loopholes to increase prices significantly year over year - and this is why leaving the middlemen in the middle was a TERRIBLE choice - but at the very least the quality of those plans still has a reasonable low bar.
I still find myself on the ACA from time to time. I can't afford it. But the plans are still significantly better and thus more affordable than what was available before.
If life was perfectly predictable then, yes, insurance wouldn't have much of a point. But alas.
We all pay in a bit and those of us unlucky enough to need a huge amount of help can have access to the resources they need. Hopefully that will never be you! But as they say: The reward for a long life is to get to experience the decay of your own body. Good health is temporary for all of us.
That said, you're right: Single-payer would be a huge improvement. Let's do that.