The you have to ask yourself: do amendments generally function globally or do they also have ‘original intent’ that must be taken into account?
For example, the 16th Amendment was sold on a soak the ultra rich basis and not as a way to heavily tax the lower and middle classes. As a matter of intent — one can say this is what the States as Sovereigns signed off on and nothing else.
Now, as per Corfield v Coryell one of our common law Privileges and Immunities was an exemption to paying higher taxes than other Citizens. Given that there was no other body of rights retained by the people at the time that the 9th Amendment was adopted it logically follows that these SAME P&I mentioned in A4:S2:C1 are also the rights that are the “others retained” in the 9th Amendment.
So, one could look at the 9th Amendment and opine that all progressive taxes are unconstitutional EXCEPT for those on the ultra rich BECAUSE the intent of the 16th Amendment altered this with respect to the federal (but not with respect to the States).
So, using the principal that amendments too have intent that may limit their application I feel safe to opine that any federal income tax that has more than two brackets — one more dear that only affects the ultra rich — is and should be deemed unconstitutional.
What is right and wrong and Constitutional is somewhat subjective.
There are needs for taxes and Congress has the authority to levy taxes.
However, is it morally right to legally force one group to pay for the sustanance of others?
Since I’m of the opinion that since God didn’t ask Isreal for more than 10% of their increase, government shouldn’t get a cent more than that from individuals no matter how they get it.