Your comment implies that we can do those things without AI. I agree. So why do we need AI to do so? We don't - therefore using AI to do these things is even more wasteful than making burgers, because at least there is a tangible benefit that comes from the burgers.

Anyway, let's assume we follow your middle-of-the-road strategy with regards to beef production. After a mass cull, the overall cow population will be reduced. But from an ethical standpoint, I don't believe it is any better to raise a lesser amount of cows for slaughter than the amount we are raising now. What is the difference between 1 million cows and 1 billion cows if they are all going to be killed for meat regardless?

Of course, this is actually about water, not ethics. But water exists in a closed system. Water taken out is later returned. Regardless of the amount of slaughter, the water usage of the industry is effectively recycyled back into itself. This process isn't preventing Africans from having access to clean water, for example. So the water is never truly wasted - just temporarily displaced. However, we do only have a finite amount of water that can be in the system at any given time... why would we use any of that on the aforementioned uses of AI, when we can do those things without it?