> much of the funding that US states are reliant on comes from the Federal government, mainly because the US Federal government is allowed to do things that the states already do and thus to require the funding for it, which means that many state programs are in fact funded by the Federal government.

Besides Medicaid, the vast majority of State-administered services are paid for through State taxes — a combination of income, sales, and property taxes. The vast majority of Federal taxes go toward Medicare, Social Security, the US Military, and Medicaid — all of those comprise 80% of the Federal budget. Besides Medicaid, none of those other things are State-level programs.

> This means that the Federal government, if it disagrees with a decision of a State, can cripple it by withdrawing funding.

This only applies to Federal highway funding. The Federal government has little control over how States fund their public K-12 schools, public universities (for eg Georgia funds its University system by taxing the lottery), electricity, water, sewage, police departments, fire departments, local public transportation, or public libraries. Further, the Federal government recently cut taxes, making way for States to fill in the gap to further cement control over their own finances. In fact, there is nothing stopping States from increasing the marginal tax rate back to WW2 levels.

> So essentially, de jure States and Provinces are more or less equal in autonomy, but in practice Provinces have much more sovereignty.

Not sure how you think this. US States are arguably more sovereign than Canadian provinces. The States exert more control over the affairs of the Federal government through its equal representation in the Senate. While Canada also has a Senate, in reality, it's like the Queen in that it totally lacks democratic legitimacy and could not actually stop major legislation from the House of Commons without sparking a Constitutional crisis. The Senate basically can force the Commons to vote on amendments, but does not block the government's agenda. This is simply not the case in the US.

Every State has its own Constitution, Legislative Branch, Executive Branch, and a State judiciary that enforces its own Constitution. Most US States even have their own military[1]. Americans are Constitutionally citizens both of the Federal republic and of the state in which they reside.

> The economies of scale that make public healthcare work require you to either control the market or a significant portion of it in order to strong arm the suppliers, A few US states such as California might be able to, but the Federal government would very likely interfere.

Yes, and every state has the ability to do this. Pharma providers, Hospitals, and doctors would be forced to accept a State single payer insurance plan, or they would have to either leave the state or go out of business. A provider in Chicago isn’t competing for patients in Florida. Pharma companies that supply medicine and supplies can either decide to accept lower revenues in a State, or stop operating in the state. The resulting vacuum from doing so presents an opportunity for new Pharma entrants (perhaps even homegrown in those states).

[1] https://en.wikipedia.org/wiki/State_defense_force