FWIW when you look at other countries, there are many out there where the word "poor" implies much less wealth than it does in US, yet poor people in those countries routinely cook their own meals. Indeed, historically it is the norm for basically everybody but the topmost layer of society.

Speaking as an immigrant, from what I've seen in US, it is mostly a cultural issue, not lack of time or ingredient availability.

UBI is a good idea but orthogonal to all this.