I’ve been to Brazil multiple times and Venezuela once, and have several close friends from both countries that have actually lived there, are politically active, and are very knowledgeably on what is going on there. First of all you have to start with the fact that all of south America is as corrupt as fuck, regardless of what flavor of political party are in power. Left, right or centrist regimes, all corrupt as fuck. Same with central America and Mexico, corrupt and extremely violent societies.
Your problem is you only see evil in right wing regimes and see left wing regimes as a solution, when the evidence says the opposite. The experiment with socialism in Venezuela has destroyed what was a prosperous country which should have the highest standard of living in the continent, and turned what was the safest country to live in or visit into one of the least safe. I wouldn’t dream of going to Venezuela now as it is extremely unsafe, in fact most of the Venezuelans I know wouldn’t go back, even to visit. This doesn’t bother you in the slightest as “left wing good, right wing bad”.
The countries that are making most progress are Chile and Uruguay, Colombia is also going in the right direction.