What's wrong with letting the specialists handle logistics so you can focus on business logic instead of basic piping?
Growing food is more like designing and manufacturing servers.
Cooking is more like taking these goods and putting them to use.
There are plenty of places that host their own servers, including people that have these servers in their home or office. But far fewer produce these machines.
You could also say that cooking food is dumb. What's wrong with having professionals chefs do it? But that also doesn't take into account the added costs which makes it unfeasible for most.
Facebook does not use cloud providers and designs their own servers.
The very large compute uses and cloud providers have incentives to grow their own food. Doing so can save them a few percent at scale. That savings is both not passed on to you and even if it was is not significant at small to medium scales.