What if there was no palm oil ?

I am being bombarded with advice to boycott palm oil because it's killing wildlife.

So let's say there was a worldwide boycott or even a legal ban and palm oil plantations weren't a thing. Are all these plantation owners going to kick back, retire and stop ripping up the forests. Or are they going to plant sunflowers instead? Why are we blaming palm oil, a specific product that makes more oil per acre than sunflowers or rapeseed? How is it any worse than growing corn or broccoli? Why should we in the west be allowed to factory farm vast tracts of previously ancient forest and third world farmers aren't allowed? Of course deforestation is a bad thing, very bad, but how can we get on our high horse and say we can do it, and they can't? Is sustainable palm oil really something we should pursue rather than simply a sustainable whole planet farming revamp?

As much as I hate regulations, I wonder if there's a beneficial way to regulate against oversized monocrops...

Even if it were just 10 acres maximum in any given contiguous crop and farmers wound up planting one combine wide alternating 10 acre strips that must have some benefit, perhaps in conjunction with contour plowing...

Better if polyculture could be promoted somehow.

Farmers are responding to the global demand for vegetable oils. You can try and restrict and regulate what they plant and how they plant it, but in poor underdeveloped areas those control mechanism either don't exist or are weak. Better, then to address the global demand side of the situation, and make it less profitable, thus reducing incentives to make new plantations. The biggest driver of demand for vegetable oils are biofuel - they divert human consumable oils directly to combustion. They increase food prices, and do little to offset fossil fuels because of all the oil used in fertiliser production and farming. And many governments worldwide pay subsidies to the biofuel industries leading to even more perverse incentives.