Yeah, these figures are bullshit manipulation. The 1% "real tax rate" figure specifically comes from a fantasy where we imagine that Jeff Bezos's net worth is his income.
I still hope Bernie Sanders is better than this, but it doesn't look good.
As a concrete example of why this is wrong thinking, let's consider that you buy a very nice house with a lake from a small secluded neighborhood that seems to be dying for $500K. Then let's further imagine that you got so lucky that the house you bought was in the center of a new town that for some reason grows magnificently over the next ten years. Things like that happened all the time in the 1900s.
Your house now in worth $20M. Should you pay income tax for $19.5M even if you don't sell the house?
There probably should be an international wealth tax that's completely unavoidable. Perhaps. Economists seem to disagree on this, but to me it would feel like a correct thing to do.
But saying that Bezos's "real tax rate" is 1% is just manipulative lying.