Farm subsidies aren't a bad idea, either. There are advantages to retaining food production within your borders, and without them, you'd probably be importing a lot more of what you eat and there are security risks there. Food has downward pressure on pricing due to external markets, and subsidies address that.
Healthcare has no such external downward pressure on pricing. The vast majority are not going to import their medical care from Mexico, South America or Asia because it's expensive at home. If you as a government want to increase access by reducing prices on healthcare, you simplistically have two ~~options~~ (edit: methods). One, increase the supply side, more facilities, doctors, and critically, more training for those new doctors (that's a big bottleneck now, since residencies are almost all funded by medicare, and that limits how many med school slots can exist initially). Two, create a taxpayer funded single payer system - a monopsonist, who is by definition not a price taker. Realistically you need to implement both options, since #2 can only impose price up to some economic limits, and those limits are determined by #1 since the current health system can't actually service everyone without significant sacrifices around wait. If you implement #2 fully and #1 to the point where you have capacity to treat everyone that objectively needs care in a timely manner, then you've implemented a functioning right to health care.
Lots of economic handwaving in there for sure, but that's how you extend the farm subsidy parallel to healthcare, and realize it's much more complicated for healthcare.