If your tax bracket is 30%, nobody expects you to pay 30% of your income in taxes. No, that's the top marginal rate, and you have deductions, and so on. This could charitably be put in the same realm -- they're getting all of their loopholes that they're dubiously entitled to.

It's sort of like if a speeding ticket costs $200. But you know you can get away with speeding most of the time. If suddenly we had a perfectly-enforced system where you paid $200 every time you exceeded the speed limit, it wouldn't seem 'fair' even though it is, strictly speaking, 'fair'.

However, to cost the average person the same amount, the amount per offense should really go down if enforcement is perfect.

In the same way, the US corporate tax rate is insanely high, but the actual amount major corporations pay is insanely low.