I don't think this is new. The idea always was that proto-humans had to live in an environment rich with energy dense food (fruit) prior to growing a brain large enough to figure out how to make barbeque. Otherwise you never get to the barbeque capable brain. The whole point of making fire and therefore consuming cooked meat is that now you can migrate to places that don't have abundant sources of energy dense food.

My interpretation was similar. The carb-sugar diet was never a highlight because it was a given. The article talks about primates that have high carb-sugar diets but doesn't explain why their brains remain so small compared to humans. Maybe they will eventually evolve? Maybe cooked meat / dense protein is the X factor? If so, that takes back to the beginning and highlights protein. It seems reasonable the combination of the two would be important. Protein enables muscle development, human evolution made us exceptionally well-suited for long-distance and endurance travel compared to all other living primates. This further improves are ability to forage and is just an evolutionary winning combination.

My curiosity leads me more towards, are their other primates that had similar / convergent evolution that independently discovered dense protein sources? Is homo sapien really just a path of singular linear "march of progress" evolution? Were there other marches of progress from other primates or any other species that we competed against or merged with? Those kind of questions become more interesting once you realize the diet combination that creates big brains

Cooking also increases the energy available from plant matter, particularly starchy tubers.

Interesting, but I've read for a long time, that our humanoid predecessors at some point figured out how to get to bone marrow with tools. That provided the energy dense food as well an evolutionary impetus to develop larger brains to build better tools and handle them better. Fire and the capability to cook were developed much later.

I don’t know how true that is. But I read a theory somewhere that people developed bigger brains when they started eating more fish which contains omega 3s.

Why is it assumed that learning to cooking animals is a necessary hurdle?

When we’re capable of eating animals raw. And bugs and worms etc.

Whereas in order to consume a wider variety of plants, cooking and other more complex perpetrations are absolutely necessary.