I think that makes sense in an academic/theoretical setting. I think it would require a massive tax/policy overhaul to make it work in real life (which would be good but seems unlikely). We seem to tax just about every level of income, but then offer all sorts of credits, deductions, etc to promote some special interest. And the special interests (looking at your TurboTax) want to keep it complicated to make money off of it. Then we have all sorts of use based taxes like property, gas, sales, guns, alcohol, cigarettes, etc.
Probably the simplest way to assign ranges of income is to apply statistics to the unadjusted pretax income in the US. It would probably make sense to adjust it based on COL too. I'm not sure what numbers and adjustments the following distribution used. I did not expect to see 10% of households making over $200k. That seems insanely high to me, but maybe that's an effect of HCOL places like Silicon Valley and dual income families.
https://www.statista.com/statistics/203183/percentage-distri...