Is it really a matter of whether voters want to pay taxes, though? Consider that in California (US), if you make 100k, you pay an avg tax rate of ~29% (marginal 41%), vs in Ontario (Canada), you pay an avg tax rate of ~28% (marginal 43%). At a glance, these look like fairly comparable tax rates.
But Ontario has free public healthcare based on residence status, while Cali doesn't. So a better question might be what is it that US taxes are paying for that are so important (but that the neighbor in the north can do without just fine) that it can't afford healthcare instead?
People all up and down healthcare earn far higher pay in the US than anywhere else.
Discussions about other causes for US taxes to be so high can get very political very quick because the myriad tax deductions available to the asset owning class, as well as the unaccounted for defined benefit / retiree healthcare debt that US governments have at all levels, and then you can get into military spending and so on and so forth.
But earning more means paying more taxes. If the tax rates are comparable, then your argument entails that the US government gets even more tax revenue than other countries per capita, so it makes even less sense that it then presumably spends those tax dollars on things that are not related to healthcare, whereas countries like Canada and UK do consider healthcare one of their priorities in their budgets, while still maintaining things like military operations and space programs.
But Ontario has free public healthcare based on residence status, while Cali doesn't. So a better question might be what is it that US taxes are paying for that are so important (but that the neighbor in the north can do without just fine) that it can't afford healthcare instead?