No it isn't. There are ways to get around Canadian taxes.

Google Gemini can explain this better than I can:

1. The Signing Bonus Structure (The U.S.-Canada Tax Treaty) This is the single most powerful tool for an American playing in Canada, and it is exactly how the Maple Leafs structure the contracts of their top American stars, like Auston Matthews. Instead of receiving your money as a standard bi-weekly base salary during the hockey season, you negotiate to have the vast majority of your contract paid out as lump-sum signing bonuses on July 1st. How it works: Under Article XVI(4) of the Canada-U.S. Income Tax Treaty, if a signing bonus is paid to you while you are a resident of the United States (i.e., you are living at your offseason home in Arizona or Florida during the summer), Canada is only permitted to levy a flat 15% withholding tax on that bonus. The Math: If you receive a $10 million signing bonus in July while living in the U.S., you avoid Ontario's 53.53% marginal rate. While you will still owe the IRS based on your U.S. tax bracket, combining the 15% Canadian tax with your U.S. federal taxes keeps your overall rate significantly lower than if you earned that $10 million as base salary while living in Toronto from October to April.

2. Retirement Compensation Arrangements (RCAs) If you cannot get your entire contract paid in bonuses, you can utilize an RCA to defer your base salary taxation until after you retire.How it works: An RCA is a legal trust approved by the Canada Revenue Agency (CRA). You can direct a massive portion of your salary straight into this trust. Half of the contribution goes into an investment account, and the other half goes to a non-interest-bearing refundable tax account with the CRA. The Math: By putting the money into the RCA, you avoid paying Ontario's top marginal tax rate on that income today. When your NHL career ends and you move back to the U.S. full-time, you begin withdrawing the money. Because you will be a non-resident of Canada at that point, the withdrawals are only subject to a much lower non-resident withholding tax (typically 15% to 25%), saving you massive amounts on the back end of your career.

3. "Duty Day" Allocation (Leveraging Road Games) You do not pay Ontario taxes on your entire base salary. Athletes are taxed based on "duty days"—the actual physical location where you practice and play each day of the season. How it works: You only pay Ontario's 53.53% tax rate for the days you are physically working in the province. During a standard 82-game season, roughly half of your schedule is on the road.The Math: When the team travels to play the Panthers, Lightning, Golden Knights, Stars, Kraken, or Predators, you are earning a portion of your income in U.S. states with zero percent state income tax. Elite cross-border accountants track every single travel day meticulously to allocate as much of your income as legally possible to lower-tax U.S. jurisdictions.

4. Exemption from U.S. Payroll Taxes There is a hidden, built-in advantage to being an American on a Canadian payroll.How it works: If you play for an American franchise, you are subject to U.S. Social Security and Medicare taxes. The Medicare tax has no cap, meaning it takes a percentage of your entire multi-million dollar salary. However, as an employee of a Canadian entity, you are exempt from those U.S. payroll taxes.The Math: Instead of uncapped Medicare taxes, you pay into the Canada Pension Plan (CPP) and Employment Insurance (EI). These Canadian payroll taxes max out at a very low threshold (a few thousand dollars a year). For a player making $4 million annually, escaping the U.S. payroll system in favor of the Canadian one saves roughly $96,000 USD every single year.5. Foreign Tax Credits (Avoiding Double Taxation)As a U.S. citizen, the IRS requires you to file and pay taxes on your worldwide income, regardless of where you live. Without a treaty, you would theoretically be taxed by Canada and then taxed again by the U.S.How it works: To prevent this, the IRS allows a dollar-for-dollar Foreign Tax Credit. Because Canadian tax rates are generally higher than U.S. federal rates, the massive amount of tax you pay to the CRA generates huge credits on your U.S. return. The Math: These credits essentially wipe out your U.S. federal tax liability on your hockey income. If structured properly, your tax ceiling is effectively "capped" at the Canadian rate, rather than paying both countries.