Point you’re missing is that glucose that is required can be produced by our body, so there is zero need for glucose or simple carbs (and arguably any carbs) in out diet.
So keto is very much the primary system, breaking down carbs is actually a “holy crap look at all this energy in our bloodstream, let’s secrete insulin and shove it all into lipid cells so that it can later be used BY KETO, OUR PRIMARY ENERGY SYSTEM”.
So keto is very much the primary system, breaking down carbs is actually a “holy crap look at all this energy in our bloodstream, let’s secrete insulin and shove it all into lipid cells so that it can later be used BY KETO, OUR PRIMARY ENERGY SYSTEM”.