Is Alberta taxed at a higher rate than other provinces? Nothing in the top few hits on Google indicates this to be the case.
And I'm not sure how the US would be different - all states pay the same federal income tax rates, whether that's individual or business income.
Under the current equalization system, Alberta last received a single Canadian dollar of direct spending in the 1964/65 fiscal year, whilst four other provinces have received over $1B annually since 2014 (Quebec, Manitoba, New Brunswick, Nova Scotia).
It sounds like I'm selling Albertan independence, but the fact that Ottawa aims for progressive internal redistribution is the exact same thing the US already has, as you point out. Similar figures of only receiving indirect federal returns can be stated for American net contributor states, too. It's the price of being in a large country, where in exchange you have a pooled currency and military that reduce vulnerabilities to external attackers.
In 2023, the federal government spent $24.0 billion including an estimated $3.3 billion from Alberta, which has not received equalization payments since 1964/65. From 2007 to 2022, Albertans’ net contribution to federal finances was $244.6 billion, more than five times the net contribution from British Columbia or Ontario, the only other two net contributors.
Albertans’ also disproportionately contribute to the CPP. From 1981 to 2022, the amount Albertans paid into the program, over and above what retirees in Alberta received in CPP payments, was $53.6 billion, approximately six times greater than the net contribution of B.C., the only other net contributing province.
This indicates Alberta (and Ontario and BC) don't pay higher tax rates. The equalization payments just come out of the general budget.
The US isn't all that much different. Wealthy states pay more per capita because it's an income tax, not a per capita tax. Looks like ~13 states pay more than they get back, with Massachusetts paying relatively more (-$5000/person) and New Mexico recieving relatively more (+$15,000/person).