Nuclear medicine? Are you talking about meat grown in fermentation chambers? Do you think that’s the only alternative to animal flesh? Those things don’t even exist on a mass production scale yet and plenty of people avoid animal products somehow. I don’t know why you think I’m advocating for such a process.
It’s also a myth that we feed animals only things that are inedible to us, edible soy and grain is very pervasive in animal agriculture. You’re also conveniently leaving out additional land, water, and energy use as inputs, as well as negative outputs (though tbf I only mentioned inputs). I’m also curious about your 90-10 ratio, I’d be incredibly surprised if in reality 90% of net energy in animal feed came from inedible crop, especially when you include pasture feeding and silage in the mix. I thought experts agreed that we could free up a significant amount of land by removing animals from our food system while still feeding the same amount of people, this wouldn’t be true if animals made our existing croplands more efficient or were at the very least neutral.