I haven't been schooled in farming, but my understanding of food has greatly increased since we started growing our own vegetables.
does that affect your cooking skills in any way?
In fact, if you divide your time between growing your own produce AND honing your cooking, both of those skills may suffer
compared to devoting your time to just focusing on one ability.
Otherwise if you try to do everything you'll never be as good as a full-time farmer or a full-time chef.
or how about another analogy:
Say one day your idea for a dish requires softer or sweeter carrots, etc, but oops you spent the last season only growing crunchier and mellower carrots, what're you gonna do now? With external suppliers you always have a wider choice of ingredients better suited to the end product you want at any given time.