I think "at a disadvantage" may be the wrong framing. As a member of (say) the 1%, but not the 0.01%, my personal take is this:
- My money does more good, dollar-for-dollar, by my own personal definition of "good", when I donate it to specific charities than when it's collected as tax and then spent.
- We would nonetheless have a net benefit from more aggressive taxation of people like me because a) the reduced effectiveness, per dollar, is counterbalanced by increased overall spending, and b) more progressive taxation would help address inequality of wealth and income, which has other, independent, pernicious impacts.
Because I believe those two things, I both a) advocate for higher taxes on "people like me" and b) to the extent legally possible, minimize my tax burden and prefer to make voluntary charitable contributions.
I believe this last part is fully consistent with the first two bullet points if we take them axiomatically, though they each may of course be themselves wrong.
Edit: I also want to add: I think when we talk policy, we often talk in a "if I were King of the World" sort of way. So, if I were King of the World, we'd raise tax rates but not spend the money on stuff I disagree with. ;) If you told me, "Yeah, we can raise the top income tax rate, but all the extra money will go to drone strikes against civilians," of course I'd oppose it. I think a lot of our "should dos" assume we get other policy outcomes we desire as well.