The plant-based burger keeps the entire architecture of the beef burger and replaces only the center, which is exactly why it is judged on a standard the beef patty never has to meet: it is not trying to be a good vegetable sandwich, it is trying to pass as a specific other sandwich. A bound patty of pea or soy protein, colored and fatted to bleed and brown, goes on the same soft bun with the same cheese, pickle, onion, and sauce as a cheeseburger. The whole build is unchanged on purpose. The plant patty's only job is to behave like ground beef under heat and in the hand, and the sandwich succeeds or fails entirely on whether that single substitution holds.
The craft is in making the patty cook like the thing it stands in for. It has to sear and take a crust on a flat-top or grill rather than steam grey, because the crust is where a burger's flavor lives and a patty that only heats through reads as wrong no matter how good the bun is. It is formulated with a fat that stays solid cold and renders hot, so it stays juicy instead of going dry and crumbly the way a lean bean patty does. It is cooked to temperature, not to time, because pushed too far it tightens and turns mealy. Everything around it is doing standard burger work: the soft bun compresses to the patty, the melted cheese laminates and seals, the pickle and raw onion cut what would otherwise read as one heavy savory note. The structural difference from beef is that this patty sheds less hot fat into the bread, so the bun stays sounder longer, which is the one place the substitution quietly changes the sandwich rather than just imitating it.
It sits inside the broader American burger family, holding the architecture and changing only the center, which is its own article rather than being crowded in here.