Is there a specific country's tax system that you look up to as the ideal?
I see often people claim that the US tax code sucks (nobody is going to defend it with the rising inequality), but there isn't any proposal about how exactly to enact the changes while still keeping the benefits of the tax code that apply to the disadvantaged.
Also, I'd like to point out that the tax code has every type of federal tax, administrative elements, and isn't just about income tax, and I'd argue that most of the federal tax code has nothing to do with "loopholes for the rich".
https://www.law.cornell.edu/uscode/text/26