We are not all the same. Some of the posters on GN are less than 50, some are over 80. Some work full-time, some retired long ago. Some are superfit, run or jog, and go to the gym daily, for some it is a major achievement to walk to the end of the road to post a letter. Some share shopping and kitchen duty with a significant other, some do it all themselves.
It doesn't have to be one extreme or the other. Cooking from scratch is therapeutic and (can be) delicious. Buying something readymade is easy, quick, and can be delicious, too .Either can also be inedible or over/underflavoured and full of fat/sugar/carbs and . A mixture of home-made and bought-in can get the best of both worlds, and the ratio of one to the other depends on individual circumstances.
Always cooking from scratch means keeping the fridge and cupboard stocked with fresh ingredients, fine if you live near the shops or you have a car, or are able-bodied enough to carry home bags of heavy fresh veg. It also means time spent on your feet preparing ingredients, standing cooking them, and washing/clearing up afterwards. Making large quantities at a time streamlines the process, but if you live on your own you soon have a freezer full of a limited choice of meals.
Always buying meals readymade is an expensive way to live, and you are at the mercy of the manufacturer on what ingredients are used and in what proportions. The same dish from two different supermarkets can differ wildly in ingredients and quality. However, once you find meals that you like, and which meet your high dietary standards, there is nothing wrong in using them when that is what you feel like eating. When you don't want the effort of shopping and cooking, (or can't do it even though you would love to) having some stored in the freezer can make the difference between having toast and tea and eating a proper meal.