The specific language you speak has significant impact here. For some, "to make food* is used to refer to cooking. Where as in English it's not so clear. I prefer the use in terms of survival. IMO, if you can make any food enough to survive you can cook, because in English there is not a better colloquial verb. Though i wouldn't call you 'a cook' or 'a chef' if you can't apply heat to produce edible food from raw.
This might be different depending on the speaker, but at least for me Portuguese and Italian are even stricter on interpreting cozinhar/cozer and cucinare/cuocere as involving heat. Like, if I were to say for example ⟨*cozinhei um sanduíche⟩ (literally "I *cooked a sandwich"), I'm almost sure that people would interpret it as "I picked an already prepared sandwich and used it as ingredient for something else"
I mean that's true of the english term as well. But if someone says they can't cook i default to thinking they order out every meal or use a microwave fot cup of ramen. Making sandwiches, salads, and other cold foods is still a skill but there's no word such as cold-cutlerist and i refuse andwich artist.
Perhaps I'm overthinking it, but the English verb seems to have different meanings when it's used transitive and intransitively. For example, let's say that you ask someone to prepare you a salad, and the person answers:
I think that's grammatically true but i tend to think of it more in terms of colloquialisms or slang. I imagine intransitive use of the verb developed out of convenience for lack of a lazy alternative. "I can't prepare food" would either suggest you require assistance to eat, you can't legally work at a restaurant, or your aristocratic status is beyond that of a mere peasant who has seen a kitchen before.