To preface, I'm not old enough to have experienced pre-ACA, but I am immensely skeptical of any Reddit community's ability to surface truthful accounts of politically sensitive recent history that would match the common experience at the time, and honestly compare them to the current day. That said,

A whole bunch of the complaints in that thread are about lifetime maximums, so the infinite potential demand theory -- "people are dumb and will gladly bankrupt themselves for a chance at one more day of life or (relative) health" -- is alive and well. If it is socially unthinkable to count the cost, the cost can get very large indeed.

If you think about it, the high end of healthcare is personalized consulting by a team of highly educated professionals who have hundreds of years of collective experience and face substantial legal risk (similar to PEs), equipped with specialized tools operated and maintained by techno-priests like the mainframe computers of old, and round-the-clock on-call monitoring, 24/7, for as long as the patient and their line of credit holds out. This is fundamentally extremely expensive. There is no cheap way to do it, and if there were, people would just do more. For example, in Modern America it is standard for each patient to have a private suite.

Imagine Elon Musk, or someone like him, is diagnosed with a rare chronic or fatal illness. The only things stopping that from consuming a Manhattan Project's worth of resources are 1) Musk's sense of propriety, and 2) the inductive reactance of deploying the money vis a vis Musk's remaining lifespan. For someone like Musk, the pool of specialists runs out before his money does and it takes years to train more, and to actually do fundamental research on his condition. It makes 100% sense that for normal people, this easily consumes the remainder of their net worth.

Healthcare cost is high because America is a wealthy nation and there's a lot of healthcare to buy. I suppose you could say that those professionals were motivated by Capitalist Greed when they pursued the education and accumulated the experience, and the scientists, engineers, and investors were acting with Capitalist Greed when they developed and manufactured the tools and trained the techno-priests. I suppose you could feel in your heart that it is wrong to do something because you expect to get paid. But I call that commie brainrot.

The only way to reduce healthcare cost is to, by hook or by crook, get people to by-and-large act as if it is not such a good idea to burn a substantial fraction of their lifetime earnings at the very end trying to eke out (at most) a few more years when their physical and mental acuity is mostly shot.

I pulled the data and plotted healthcare cost as a % of GDP. Maybe the ACA at least slowed the rate of the problem getting worse?

As for only being available to healthy people, at that point you're not talking about health insurance. Can't insure something you don't have.

On the subject of drugs, I recommend this 90-minute podcast if you feel like it. Alas, the host uses complicated syntax, so it's difficult to understand above 1.75 or 2x speed.