Exactly. I once visited a seed bank and there was some text along the lines of “we store these seeds at -60 °C which is 3 times as cold as your typical freezer” (for Americans: a freezer typically is about -20 °C). Yeah, no, that’s not how it works. With Kelvin you can actually do math like that, because 0 K is the absence of heat zero thermal energy.
In my opinion it’s more useful to look at grams of protein per kcal. You can only eat so many calories in a day, so that dictates your protein intake for a large part. If you eat 2000 kcal worth of peanuts, you’d ingest 80 grams of protein. With chickpeas that would be 110 grams and with chicken breast 425 grams. You don’t eat just protein rich things, so the higher the value, the higher your chances of ingesting enough protein when combined with (other) vegetables, grains, rice, oil, etc.
I know that some people will read this comment as if I’m promoting meat consumption, so let me add that I firmly believe that the world would be a better place if we ate a lot less meat. I’m just using these examples for demonstration purposes, as they’re all at the right side of the graph. It’s always an option to supplement with a plant based protein powder.