I accept that "organic" labels are gimmicky, but the alternative is to eat food that is not certified organic, and that hasn't been enjoyable for me. Organic natural food may or may not look better, taste better, and have better nutrition, but in hockey terms, "You miss 100% of the shots you never take."
(An organic certification is not my sole criterion for food selection, either; I factor in plenty of others.)
I mean, organic food is probably not causing you any harm other than potentially financial, so that's fine.
The best food advice IMO is to ignore 99% of what's in the supermarket, and buy mainly fresh meat, fresh fish, and mostly lots of fresh fruits and vegetables. It's not even a particularly accurate heuristic, but if people ignored anything that came in a box or can, people would probably be 10x healthier.
When I chose to shop at a farmer's market-style grocery store, it came as no surprise that 99% of it is processed, loaded with sugar, preservatives, and all the same tricks you'd find in stock at a 7-Eleven. A "health food store" is still a supermarket with different brands.
I'm beginning to get a feel for which brands can be trusted, vs. which ones are purveyors of junk food.
Your rule of thumb is 100% correct, but I needed to pace myself. As a sedentary, novice cook, I couldn't handle hours in the kitchen prepping everything from scratch, 3 times a day. I was so exhausted, I had to use an electric scooter inside the grocery store! Healthy food is labor-intensive, and it seems like there is an intrinsic direct correlation to that. Healthy food even takes more work to digest!
But if food is frozen or canned or shelf-stable, caveat emptor indeed.
I'm not really knowledgable about food and health, but my familly in general is great at cooking (it was my sister's job for six years, and tbh, she learned more from our father than her first starred chef).
Here are my tips for fast food:
First, stewed dishes are the best. it "takes time" to prepare, but actually it doesn't: just cook it while doing something where you can be interupted - like two hour meetings, video games (set a 20 minute clock in this case) or during a weekly house cleaning- and it actually takes no time. Great stew i like to do are ratatouille and Bortsh, Ratatouille in summer, Bortsh in autumn-winter. I also taught myself other dishes i can do in a steawpot for multiple day, like the indian Dahl, but it is a bit more hard if you don't know your spices yet.
Second: always have carrots, radish and cauliflower in your fridge, and do not hesitate to take them out every meal (you don't have to, but still). You can dip them in soy sauce or make your own yoghourt-base sauce, which is quite easy to prepare. Plus, carrots, cauliflower and broccoli have another secret preparation tip if you'r lazy and just want to cook pasta or rice: add those vegetables to the cooking water and boil them. Once the pasta are done (since it takes less time than rice usually) and if those arent cooked enough, just stir them with curcuma, pepper and a bit of salt for ~2 to 5 minutes on a frying pan. This is a great way to learn your way around spices, without taking too much time (its like 4 more minutes than regular pasta).
Only tips i have at the top of my head right now. I have other tips for cleaning/cutting/peeling that i was taught, but those are hard to explain through the internet.
(An organic certification is not my sole criterion for food selection, either; I factor in plenty of others.)