You need look no further than the other side of the Columbia River to see the trade-off. Most years, Washington has the most regressive tax regime in the United States, Oregon has the least regressive. Oregon has an income tax and no sales tax.

Are the proposals for adding income tax to WA going to also reduce the sales tax in equal measure so that the states total revenue stays around the same amount?

What specific effect are observing to compare outcomes? OR has better strip clubs and more people blocking urban intersections and lighting stuff on fire.

I don't think I'd go that far. Except for the strip clubs, that's definitely a plus. We do know how the tax is distributed by income, however, which may be the only useful metric (absolute values having not much to do with method, I assume).

WA has high sales tax. Poor people pay a larger portion of taxes in WA compared to elsewhere.

CA has income tax and the sales tax is just as high.

> CA has income tax and the sales tax is just as high.

CA also has a property tax and capital gains tax.

Oh yes, and a business income tax, and a franchise tax... honestly curious if there is a tax that California doesn't have...

And yet somehow people keep moving there, and the NIMBY crowd keeps doing its best to keep folks out.