> It boggles my mind when I still occasionally hear people speaking out against all forms of single payer healthcare in the US saying they don't want to have to wait weeks/months to see a doctor like they do in Canada/UK/wherever.

Conversely, people consistently put forth single-payer as a panacea without considering what other differences exist between the systems.

For example, in the US a medical residency is required by law but the number of residency slots is constrained because the AMA wants to reduce supply/competition. Change who pays the premiums and that's still just as much of a problem, and it might even make it worse to give the lobbyists an even deeper pocket to siphon money from.

Another significant source of costs in the US system is that doctors can prescribe much more expensive patented drugs or devices and no part of the system is given the incentive to say no to something which is only slightly or negligibly better but dramatically more expensive. Likewise, many of these patents are obvious (e.g. extended release version of existing drug or combination of two common existing drugs) and shouldn't be granted, but nevertheless are. But if those patents are issued and the system is required to pay for a drug when a doctor prescribes it, the seller has a monopoly for the patent term and can charge the monopoly price. The normal way to solve that is for "customers" to be more exposed to cost differences between treatment options, so that things that are only marginally better can only charge marginally higher prices, which is the opposite of how single-payer works.

"Single payer" is essentially replacing insurance companies with the government, but that doesn't solve any of the problems that exist in the parts of the system that aren't the insurance companies.