It's mostly being used for agriculture.
Then it's gone. Forever.
No. In fact, evidence suggests most of the rainforest was in fact laid by humans. It's artificially mostly made of trees with edible produce like açaí and brazil nut.
When the forest loses the capacity to create clouds, it is game over. It will never be the same again, and that's just one of many of non-linear effects at work.
Apparently the global human mass excluding humans themselves who comprise 0.01% of the global biomass but including our constructions in concrete, asphalt, aggregates, bricks, plastic & glass exceeded the global biomass back in 2020. The same report claims that this anthropogenic mass doubles every 20 years. I wonder what the thermal capacity of all this is let alone other manifest concerns.