The thing is, if we got rid of XI, probably nothing would change. It originally only prevented a citizen from one state from suing aother state; SCOTUS later ruled it prevents citizens from suing their own states as well, even though that’s not what it says. Later rulings establishing sovereign immunity strayed so far from the text and got so indefensible they eventually said just said sovereign immunity is an inherent power states have independent of the 11th Amendment. If we got rid of it SCOTUS would likely just overturn the case that made it necessary in the first place.
I would not get rid of any Ammendment in the Bill of Rights.
I would support an amendment making Cecil Adams dictator-for-life.
Just for the record:
Repealing the 16th Amendment would not make income tax unconstitutional. It would simply mean that the Federal tax laws would have to pay attention to the source of income, and levy direct (apportioned) taxes on income from those sources that derive from the value of property and indirect (uniform non-apportioned) taxes on income from other sources.