We’d have to allow for some definition creep, effectively freeze healthcare innovation, or let the basic level of healthcare fall to below basic after years of improvements and new drugs
So I think the state owes its citizens some modicum of health insurance, but it's not there to provide for non-basic health care --that which keeps a bell-curve fitting person in reasonable health for a reasonable amount of time (to be some independent health-body defined arbitrary time). Anything more should be up to complementary insurance of some sort or another.
It may come to be that like cars, all cars even the basic ones upgrade their Window hand-cranks to automatic. However, that should come from an economic feasibility point of view rather than 60% of voters/deciders say they want it.
Supporting people staying healthy, preventing diseases is a whole lot cheaper eventually. The idea behind universal health care is that you don't want to be overly stringent because it comes back to you down the line with vengeance. In my country for example you are recommended to visit the dentist at least once a year because prevention is important, and society can't exactly function well with people having bad teeth. Equal chances and all that, but also to avoid the cost down the line. In the United States however nobody cares, there isn't even a society, just a bunch of different classes living very different lives. If you can't afford good teeth you don't matter. You are not good enough. Problem solved. Good luck making it with your bad teeth. That's your problem, why should I pay for it. It's funny when people who call themselves Christians say this when Christianity is about realizing the eventual spiraling cost of not landing a hand to people, although this practicality evolved into morals over the ages. In the United States however there is a deep cultural problem, a lack of practical morality if you will, and that's not going to be easily solved.
I don't think we disagree that having a healthy population is good for a functional society. This requires preventive and maintenance healthcare "needs" --but would not include "wants" like cosmetic and elective options. If your eyelid droops but you can see well, I don't think that's necessary. If your hair is falling out and you want implants, if your mammaries are small or drooping I don't think elective options are necessary. We need to keep people healthy, we do not need to keep them attractive. So for Example I would not include "ED" --that's independent of health.
improved treatment for an existing ailment or condition should be considered covered under universal healthcare coverage.
I think it's cosmetic surgery or non-health-threatening treatments that would not be covered.
There's a question to be asked here though: would treatments such as laser eye surgery, where the condition being treated _already_ has an existing, cheaper treatment, be considered covered?
I would not expand the definition of basic to cover any cosmetic and or elective procedures. And also not to introduce definition creep.