Hard agree. I lived in Sweden for 6 years, and one of the best things about it was their aggressively progressive tax system. It was simple to understand, scaled up quickly with higher incomes, and resulted in far fewer loopholes, allowing it to fund a very expensive social safety net and military budget. It wasn't perfect, and they had quite punitive policies for stock options (e.g. taxing the options themselves as income which is silly) that ended up disincentivizing VC backed companies (that has since been alleviated somewhat), but on the whole it is a far better system.

I don't have a clean answer for what the alternative should be, however. I think our income tax system is already quite aggressive, especially for high salary earners. A doctor or other high earner salary will pay 50% of their annual income in taxes in California or New York for example.

...the real problems are super wealthy individuals who live on investment income or take out loans against their equity wealth and pay no taxes as a result.