Just my guess which may be wrong, but my guess is those real beef burgers are probably made out of some beef by product like the pink slime or something. Might technically be beef based, but not what you picture as ground meat. Friends of mine worked at a plant that made hot dogs as one of their products, told me you'd never eat another one if you saw what went into them.
Ain't that the truth ha ha !!
A friend of mine - in the mid 1980s - he worked in a hot dog factory in NYC that also made shoe laces, the stories he told us had the whole gang keeling over !!
Someone else we knew worked the weenie wagon @ Coney Island, he had some pretty funny stories as well about the cooking utensiles melting/corroding over time.......
As for the impossible burger, I'm told by another friend who has a real passion for cooking good European food, he said it tasted like cardboard and the impression he got was it seemed to be very very unhealthy due to it being highly processed which makes sense, I mean seriously - you see these vegan gals, they are either as big as houses or they look like death warmed over they are so skeletal.... I have yet to see a vegan gal who even remotely appears to be healthy [*I have yet to see one who is indeed healthy...] which might be the real reason there's such a push for this so called vegan lifestyle - because it will make the medial industry even richer long term....