I feel like this is one of the fundamental issues with US taxation today and this overall issue of wealth inequality. People like you, high-income and likely not a lot of shelters for that income based on what you're saying, pay a lot of taxes percentage-wise and so the thought of paying another 1-2 percentage points is, for lack of a better word, sickening. I tend to think you're right about that because it feels really unfair when you're paying 40-50% tax, a lot of people pay zero, and then people who are much wealthier than you are paying 20%.
It's when you start making fabulous amounts of money, and can park it in all sorts of shelters, whether that's straightforward things like real estate or, as HN commenters point out every time this comes up, by not ever even earning income or investment gains and so you can drive your tax towards zero (by doing things like taking out loans against your assets for money to live on).
I'm not sure what the answer is, but a North Star, in my mind, would be that as you have more you pay more, a truly progressive scheme, because every additional dollar you earn (through income or investment gains, realized or unrealized), as you get richer, actually is less critical to your livelihood. Who am I to say that? I'm not talking about some nebulous concept. I'm saying that if you make $1 million dollars per year, in total, a dollar extra matters less to you than it does to someone making $100,000 so I'm purely speaking on a relative basis (cue someone saying "how do you know it matters less? That person could live in a HCOL location, or have 12 kids or..." Hopefully we can avoid that because it misses the point; those things are choices people make. How much you're taxed is not a choice for the most part though can be to some extent (move from a high-tax state to a low one, etc.).