My understanding is very challenging for a few reasons.
1. A forest is not just a bunch of trees. It’s most healthy and robust with mature trees and right animal life that supports and propagates them
2. The short term economic incentives towards rehabilitating the forest aren’t there and are actively counter productive for soy and beef farming
3. It might already be past a tipping point as some parts of the forest are dying out and setting on fire through natural causes. The Amazon rainforest is NOT an ecosystem that is used to burning and it cannot recover from it since it destroys the ground cover and soils rainforest plants depend on to grow. Plants that like wet conditions need wet conditions to prosper, dusty charred clay ain’t that
And even if it's somehow possible, it takes a lot longer too. Unless you're just moving the trees from somewhere else (which kinda defeats the whole point), you need to grow new ones, and trees take a pretty long time to get as large as the ones we're talking about.