The wait time for an American at the poverty line seeking care for an expensive but non-emergency chronic condition can be effectively infinite.
My wife receives treatment for chronic pain. Getting treatment at a pain clinic started required five visits (including being able to physically get there in the first place), lab work, etc. Each of those required a hefty co-pay, and someone on a Bronze ACA plan will have a multi-thousand dollar deductible to meet before even those kick in.
If you're working minimum wage and have a pain condition, treatment is likely inaccessible, even if you technically have fully subsidized health insurance.
Anything that requires ongoing treatments or regular doctors' visits is going to be largely inaccessible to a low-income person on a high-deductible plan.
To me, the NHS in the UK is run by the NHS (chiefs, trusts, executives, etc). It's funded and meddled with by the government. But it outlives each successive government.
You'll hear far more positive stories than negative ones if you ask any one in the UK.
My kid spent a week in infant ICU. Cost to me zero. Total cost of pregnancy zero. Time thinking about the cost until now zero.
Money and healthcare are two exclusive concepts to the average British person. If we thought more about cost and healthcare maybe people would be willing to pay more tax for it. But they think it's free.
The same applies in the US in terms of health coverage. The outliers are more vocal and more screwed but not a majority by far.
In reality, "negative stories" aren't much of a strong signal. There are likely as many "positive stories" that don't get as much traction, particularly because there is quite a lot of effort invested in the US into spreading FUD about single-payer healthcare systems. Though I do agree that this effort is effective on many people.
edit: I do love echo chambers, someone asks a question about why a certain groups thinks a certain way, you answer and you get downvoted. Why bother being on a discussion forum if you don't ever want to hear what the other side sees things as even when directly asked? Especially amusing since I do support universal healthcare but actually try to understand why people oppose it rather than covering my eyes and ears whenever they talk.