AFAICT this is not a matter of small farmers clearing a bit of land in order to survive. It's a matter of huge cattle producers and industrial soy farms burning clear vast swathes of the Amazon jungle, for profit.
And producing soy in Brazil has become even more profitable now that the US vs China trade war is in full swing and the Chinese have stopped purchasing US soy. There’s no easy solution for this in an world as inter-connected as ours, apart from breaking all said connections (for example the Chinese reverting to only eating things that they actually grow in their land, which will most probably create a mass famine or two) or somehow for us to consume a lot less things, which hasn’t been the case for at least 200 years (since the Industrial Revolution started).