Cows etc get the nutrients from plants. For a start I am not sure how many vegans can actually process hard plant matter as we are not ruminants. Maybe if they ferment said vegetable matter in big vats they could make use of it. But then the methane and co2 produced would at the end of the day equate to that produced by animals. After all physics and chemistry obey laws not opinions or whims.
The animal after all is a biological factory carrying out chemical processes.
Turning raw materials into other products still uses energy and has biproducts.
You won't have animals in ace you'll need masses of factories in their place to process plant matter.
The vegan milk article recently had me chuckling, not sure how much almonds rice or soy we grow in the uk? But it's okay ignore the transport costs, what's wrong with water we get plenty of that locally.
Most vegans get their protein from beans and pulses. Not much processing needed and if you grow the right crop for the local climate you can produce far more protein per hectare than you can doing it with animals. In the UK Borlotti and Broad/Fava beans do especially well. In upland areas where the only growable crop is grass then lambs make a great deal of sense.
Any UK-produced meat is streets ahead of even EU-produced meat (think about the poor welfare of Danish pork, for example) but it's orders of magnitude more enlightened than say the feed-lot raised hormone-pumped beef in the Americas.
You're quite right about all the strange 'milks', though. The only one that makes sense to me as a milk alternative in the UK is oat milk, fortunately that's quite palatable.
For us it's a balance between animal welfare standards, minimal/zero processing (everything gets cooked from raw ingredients) and food miles.
Today's dinner was pea and mushroom curry with basmati rice and a side dish of sag aloo. The only non-UK elements were the rice and the creamed coconut.
Yum Yum!
