People have attached pens to 3d printers and used them to write letters, effectively print. Most consumer 3D printers are useing or based on open source software.
I think the issue is, printers are relatively cheap to buy and replace. So building your own and programming it hasn’t been necessary. Where as 3d printing was completely in accessible before the reprap movement. 3D printing software is open source as it is motivated by people wanting to build their own machines that could build machines. Something you couldn’t easily buy.
They also produce much more meat. They also eat indigestible (to humans) food. Cows stomachs can eat and gain calories from grass in a way humans or dogs can’t, for dogs and humans grass is fibre and doesn’t provide many calories.
Cows are great in this case for food security, ground that would struggle to produce much grains or vegetables can still produce grass. If you feed your cows a lot of grains the food security aspect is nullified. Even feeding dogs grains for a country like North Korea that struggles with food security is not a rational unless the dogs provide a benefit like guard dogs etc. During World War Two many people in UK cities killed their dogs when rationing was put in place (not to eat) purely because it was suggested the pets would consume food that could have been human food.