You do sound busy. I am lucky that i am currently in a "sweet spot"--no aging parents to care for (no idea how we'll manage that---my parents live in Mexico and I, an only child live in Germany, it is something I very much worry about), I volunteer a fair amount but do not work, both kids are grown . . .
But even when I had a newborn and we lived in a little trailer out on a cattle ranch 40 miles from the nearest store and were so broke that paying gas for me to drive to town just to shop was so not in the cards, so I rode in with DH once a week, fit in all errands/doctors appointments/etc and did whatever else I could think of to entertain my little one or keep my baby out of the elements and then bought groceries at the end of the day to get through until the next week---I still cooked the portions we'd eat and did not do leftovers.
For ME, being the way I taught myself to cook and am used to, that is faster, easier and less stressful than following recipes and making big batches. I suspect for someone used to cooking in larger quantities and measuring things trying to cook like i do would be more time consuming---there is a lot to be said for being in a routine --regardless of what the routine itself is.
(by the way---I doubt I spend more time shopping than most anyone else here, assuming they don't have it all delivered. I walk or bike past the places I duck into anyway, and am nearly always in and out in under 10 minutes. Small stores, i know where things are and there is rarely much if any line at the times of day I end up there)