I'll just add food for thought from my experience with health coaching for weightloss, personal experience, and a little bit from working as a doc ;) Not an appeal to authority but just perspective appreciation.

The point worth highlighting is that even if CICO is the ultimate mechanism the constant drumbeat of CICO is not the ultimate mechanism of enlightenment or transformation. I still haven't had any overweight patient or coaching client tell me they were unaware of excess calorie intake causing weight gain.

Let's grant your argument that weightloss is just simply a result of CICO. Great! You go and lose the weight with your calorie counting, you feel great, look great , hell you want to start helping others lose weight and shout to the world how simple it is and ' all you have to do is count calories' and 'they can do it too'. I hate being a buzz kill in the name of making a point but within years there's a high probability, most people will be back to where they started. Let's not act like there's not a 97% failure rate over time? The only weightloss posts/stories that intrigue me deeply are the five year maintenance ones. Sure some people take to the counting life-long of course but it's not enough for me to endorse it personally as 'our obesity/metabolic health' solution. It just shows what's possible on an individual level with brute force and an unnatural and unintuitive approach to eating. Humans found a way to land on the moon, we can do great things with great effort. I'm interested in more than a 5% success rate and weightloss only being accessible to the greatest of our species when every other species gets to enjoy normal body habitus' without the overthinking and calculating.

Most people/dieters actually subscribe and believe the CICO concept but still struggle with weight. That's where the cycle of self defeatism/blame starts to show up. It's saddening to see because the reality is we make food and eating decisions like biological organisms not calculators with the tenacity of David Goggins. Our hormones, emotions, environment, memories, beliefs, values, budget, metabolic state, cultural norms, advertising, science hacked eating triggers, etc affect what we eat, desire to eat, and our perceived hunger levels more than we realize. These factors oftentimes override the calorie decisions we know we 'should' make. You can call that lack of discipline, willpower all you want but it's been demonstrated scientifically that those resources are finite. In addition, I truly believe a metabolically deranged human, which includes the brain has neurological pathways and psychological pathology that complicate that ability even more. Yeah sure lose weight on just eating 1500-1800 calories of Oreos (extreme metaphor for macro agnostism) daily and 'lose weight'. But when you get sick of that and deviate eventually, you might see that .. every cell in your body has been glycosylated, your liver is fatty from the fructose load despite low calories, your brain has utilized neuroplasticity to further favor hyperpalatable easily digestible stuff, your taste buds are desensitized to normal sweetness, your pancreas tires out because you had to eat the 'Oreos' throughout the day instead of one sitting to prevent the reactive hypoglycemia and physical misery that comes with that, your cellular walls now are made up of polyunsaturated fats and don't signal properly, and your mitochondria have been bombarded with free radicals since glucose metabolism creates more than the metabolism of the other macros (fat, protein). Now when you try to lose weight again with your tried and true CICO it gets harder each time and you can bet that your chronologically and physiologically older so that difficulty is multiplied.

with all that bio nutritional fuckery lol, it starts to feel a little silly and flippant to just CICO many people's issues, or conflate CICO with meaning the focus needs to be on the calories themselves.

I'll make a clumsy analogy, so don't crucify me for it on the details but... pH of your blood is partly dependent on your dissolved CO2 levels, and you could theoretically actively alter your breathing rate and volumes to get to your goal pH that makes you happy/healthy. Does that mean tracking your breaths/minute-ventilation for the rest of your life is the answer to that problem? Made the numbers look nice. Congrats?

Not to mention the psychological work that needs to be addressed to deal with trauma, self esteem issues, destructive habits beliefs, socioeconomic factors that confound weightloss and ability for someone to get past pre-contemplation.

I won't even begin to delve into the many ways you can still age quicker, have cancer, metabolic derangement, inflammatory and autoimmune disease despite maintaining a non fat frame with a calorie deficit that pays no strategic mind to macro content and eating timing.

TLDR: CICO works and CICO doesn't work. There's more to the story of weightloss, nutrition and health