You mentioned a ton of things that change (which, sure, they do, after all it would be weird if, after processing when things taste differently, nothing would have changed), you did not make the causal link to things changing in a way that is detrimental to health.
Just because it changes doesn’t mean it‘s bad.
Even your only point where one could argue that there is a potential obvious negative health effect (the vitamins) is only an issue if there are actual vitamin deficiencies that matter.
> is only an issue if there are actual vitamin deficiencies that matter.
It's an issue because it's wasteful, you're loosing the good stuff in the process. Throwing half of your meal into garbage every time is only an issue if you're still hungry afterwards, but it's not economically and ecologically sane thing to do. This is a similar thing, one should try to maximize the use of food that they pay for.
Cooking meat allows your digestive system to ingest more proteins, for example.
This is why fire was such an unprecedented step in our evolution.
For example:
Raw egg: 3g of protein at most.
Cooked egg: 6g of protein.
Just because it changes doesn’t mean it‘s bad.
Even your only point where one could argue that there is a potential obvious negative health effect (the vitamins) is only an issue if there are actual vitamin deficiencies that matter.