Personal income tax dodging is bad as that is where most tax revenue comes from. Taxes should probably be lower on income as well though to discourage tax games and retaining more tax whales (wealthy tax payers). People of all brackets need more money in their pocket for this consumer economy that hasn't really rebounded.
https://www.bloomberg.com/news/articles/2017-04-11/sorry-ame...
How low is low enough? Pay your damn taxes.
There are lots of taxes beyond income tax. Basically taxes take about .35-.50 out of every dollar earned through income, sales, other taxes. Business expenses for businesses, kids, credits and other things can help bring it down as well as standard deductions but it is still high.
They also don't include self-employment tax (15%) and sales tax (6-10%). Sales tax and self-employment alone are over 20% close to 25% not counted in the article. Property tax can be close to 1% (depends on property), dividend taxes also aren't included (10-15%).