Both can be true: it is too expensive, and there’s no money to be made. $840B wouldn’t put a dent in the launch costs for the tens of thousands of rockets we’d need to put into space over the next several decades in order to just get rid of the Pacific Garbage Patch, to say nothing of the rest of the trash on this planet.

And actually, there’s a third true thing: it wouldn’t help much. Having it on Earth isn’t the problem; it’s having it in the oceans that’s the problem. Partially because of the environmental impact, partially because of the biological impact, and partially because we don’t have access to it to reuse it, so we have to keep making more. Once we had it out of the oceans, we could recycle it or even just sequester it away.