When I was 7 and my brother was 10, we moved. With the move, we became latch key kids because a school bus could drop us at a park very near the house which hadn't been true at our previous home.
It also meant, because we now lived in earthquake territory, that there was a possibility that we might end up at some point caring for ourselves in an emergency like a major earthquake for a day or two if they struggled to get back from work due to infrastructure damage (like bridges).
We'd been taught from a very early age to cook - helping as soon as we were able to improve motor skills as @moniquill says above - and could both pretty confidently prepare a few things.
Due to the new situation, my mom spent a Saturday in the kitchen with us, working through how to make 4 things from pantry/fridge staples (no ingredients that wouldn't generally be kept on hand) that we would definitely be willing to eat to ensure we wouldn't starve if that happened.
And my dad spent time teaching my brother to safely use the camp stove if we lost gas/power in that circumstance (he would do the same with me a few years later, but at 7 I was both a bit young and a bit of a fire bug).
They did these things, both teach us growing up and teaching us more in this specific circumstance because cooking is 1) a survival skill and 2) a teachable skill with numerous levels of knowledge (starting at 'toddler, move this spoon around this bowl') making it great as children grow.
And acting like kids aren't competent to be taught to feed themselves is just another way to take away their agency and independence. Stop infantilizing teenagers. Stop infantilizing 8 year olds. They are functioning human beings with functioning human being skills and should be treated as such.