Why would the poor be poorer? How about we just produce, what we need and give it to the people who need it? With noone between, skimming billion over billion. We may not produce 1500 different types of cars and 2600 types of different strawberry-yogurts. But who gives a feck about that?
Again, you are not able to even imagine a fair world. When you put a single developing country out of the global capitalist economy, of course it wouldn't fare well. The change will have to come globally. And it will, but as things stand in a different way, then I'd hope for. Climate change will probably lead to some kind of fascism. To rich countries shooting climate-refugees from their borders, while struggling inside the borders with natural disasters and crop failures.
This Churchill-quote, you might have believed it 60 years ago, but to cite it today is beyond me. Everyone with eyes can see that this system, that is driven by the delusion of eternal growth will kill the environment. It will kill our children and grandchildren. We have to come up with another system. Like we changed from feudalism to capitalism, we have to change now, or it will have catastrophic consequences.
You may say that a social-democracy like in the Scandinavic countries is the way to go. But they also lived way beyond their means while still profiting from global injustice.