We should definitely encourage schools to renovate and make use of the kitchens when they have them, encourage kitchen facilities be included in new construction, and maybe even encourage creative solutions when no other options exist.
Some hopeful example :
Quebec hospitals started cooking all their food internally on the same budget.
More and more French municipalities stopped their frozen food subscription to hire a handful of cooks and gardeners with a similar budgets. ( those are minimum wages jobs than can be sourced locally )
To conclude : human have been cooking food in batch for quiet a while. That what I mean when I say « we forgot » : some communal facilities like school don’t even have kitchen anymore.