> And very useful because their hives are large and portable.

I have no proof of this, this is just my theory, but the "portable" might be the issue. I think industrial beekeepers in the US might be part of the problem. Yes you can technically move the bees, but should you? You're moving around disease, you might be overworking and stressing the bees. Meanwhile you have farmers create massive fields with nothing but corn, grass, wheat, whatever, leaving you with essentially green deserts from the pollinators perspectives.

Again just a theory of mine, but the reliance of "portable" bees is what's causing the problem. Other countries have beehives for rent, but they aren't moved constantly. Often they stay in the same location all year and the bees are allowed to follow their natural cycles.

Trucking around hundreds of hives always seems rather stupid.