Do you think that's actually why Bolsonaro is in jail? (He attempted something of a coup after losing to Lula, who in bemusing fashion had been imprisoned by Bolsonaro.)
How are you folks such suckers that you think the far right wing Twitter takes on USAid and South American elections are accurate? You are citing a story below the USAid spending in Brazil went up in 2019 when Bolsonaro was in power. Who was the President from 2019-early 2021?
The truth is, South America has moved right because the left is generally not very good at solving problems, and so voters down there are probably not impressed by it. The issue is that the populist right hasn't been very good at solving problems either (with some exceptions, as populist right wing parties tend to be better on some matters ala crime). Of course, some of the South American right wing governments aren't populists (Milei in Argentina is basically a libertarian nationalist, Chile has mostly been governed by a pretty reasonable right wing, and so on). That said, USAid or no USAid, the right-leaning governments will have to govern effectively to stay in power, so at some point the South American left will have a resurgence that has nothing to do with USAid.
I wish the best for our South American neighbors. I suspect their right wing governments will be better than the left wing ones, but that ultimately the death of USAid won't save them if the public finds their own governance lacking.