The reason not to move to WA is the capital gains tax in WA is unpredictable. Someone else had explained that it’s actually against the state’s constitution but was upheld by the one sided state courts. And the legislators adjusted the rates upward once already even though it’s a very new tax. The state budget is in a bad shape and expected to get worse, so it’s likely they’ll keep increasing the tax every year.

The stock market is growing, salaries aren't. Makes sense to tax the former and not the latter.