They lack all the essential amino acids, but you can easily circumvent that by combining sources. People have been doing so with combinations like rice and beans for generations. But the question is whether the calories cited come from enough variety to meet those nutritional needs. Again, all calories aren’t created equal.

I don’t disagree that western societies probably eat too much meat. But that is the trend of any burgeoning middle class, and it’s doubtful it will change.