Plant protein also contains all essential amino acids. Even broccoli.
500 calories (150g) of TVP (soy chunks) has 100%+ of each EAA while 500 calories (200g) of steak is sub-100% in three EAAs. The soy chunks also have 25g more protein than the steak. I use it in all recipes that call for ground beef as it's similar is texture.
The 500 calories of soy chunks also has 59% of the day nutrition while the steak only has 47% (source: Cronometer).
Seems to me that if you're going to bring up a concept like incomplete protein (which I think is a nonsensical concept), you'd have to bite the bullet on steak being incomplete and plant protein being superior.
I dismiss the concept because we aren't limited to 500 calories per day. But if we were, I'd rather be stuck with TVP.