You're not going to get the same level of protein from kale as you would from a chicken breast. You'd eat so much kale you'd be sick.
Secondly, plant proteins have incomplete amino acid profiles and won't stimulate mtor the say protein from meat and dairy will.
I’m not saying people find it hard; I literally can’t think of 3 foods that are both low net-carb and low protein-per-calorie.
Olive oil & butter are the two I’ve come up with so far. Any others you can think of?
ETA: someone else suggested avocados too. Any others?