The Impossible Burger is supplemented with a ton of B vitamins (for thiamine, several weeks' supply).
Most vegans eat lots of other B containing foods, including yeast (which is after all how plant-eating animals manufacture B vitamins in the first place, by fermentation during digestion). But for those who want to get it along with their protein source, the plant-based meat-simulacra also contain it.
The only reason most meats have B12 is because the animals are supplemented with it as well, because modern farming has sterilized to the point where even these animals don't get enough naturally.
So either way your B12 is coming from supplements. It's either in a pill already, or the flesh of animal who didn't want to die, and they simply took the pill on your behalf.
This is silly. The solution to a vitamin deficiency is vitamins. Clearly they're deficient while eating meat too, so that doesn't seem like a strong argument against plant based proteins.
No, they are not "clearly deficient while eating meat" as you claim. There's a documented B12 deficiency in vegans and vegetarians that isn't present in meat eaters.
Cherry picking one vitamin deficiency in vegans. Omnivores are deficient in other vitamins. The answer is supplementing, not changing foods you eat.
> Omnivores had the lowest intake of Mg, vitamin C, vitamin E, niacin and folic acid. Vegans reported low intakes of Ca and a marginal consumption of the vitamins D and B12.
https://www.healthline.com/nutrition/impossible-burger#what-...
The Impossible Burger is supplemented with a ton of B vitamins (for thiamine, several weeks' supply).
Most vegans eat lots of other B containing foods, including yeast (which is after all how plant-eating animals manufacture B vitamins in the first place, by fermentation during digestion). But for those who want to get it along with their protein source, the plant-based meat-simulacra also contain it.