I think the point being made is about the "density" of protein per serving. Sure you can get 75 from PB but that would also give you diabetes, and excessive fat too.
Same goes for plans, yes in powder form it's a few scoops but you probably would be way too stuffed if you eat the actual veggies.
On the other hand, 95% of Americans don’t eat enough fiber, which means they aren’t getting any of the other benefits of plants like vitamins and antioxidants.
I’d wager that’s much more important than the average muscleless flaboid getting 150g protein.
But my point isn’t that, it’s that for an average person eating average calories it’s not difficult by any means to get enough protein.
To be fair though, plant based protein powder is about 700 calories for 150g of protein too :)