We have all sorts of meal plans of the home delivery sort in this area for all sorts of reasons from health/medical to religion to simple convenience. You can have foods completely fixed and portioned for you. You can have meal kits that you cook yourself to various degrees from a little bit of work to a lot. You can pick what you want, or you can get what they give you.
The one couple that I know that loves their plan is "dinks" dual income/no kids. They are active/recently retired and like to cook but they don't like to shop, and they don't necessarily want to pick what they are having. I think they get about 5 meals per week, for them it is also cheaper than going out. I've had benefit of a package or two when they've had emergencies come up and had to go out of town.
I had another friend who thought this would be the answer to her prayers, she always claimed she didn't have time to shop or cook or be healthy. But it turned out she didn't eat the healthy foods either even when they were prepared in advance and there...
For those of us who have to be serious about changing the way we eat, I think they can be very helpful. They show you portion sizes and give you options maybe you wouldn't have tried yourself. As always, our attitudes are probably the biggest thing. That and our willingness to rid the house of the things we shouldn't have and/or our willingness to eat things maybe we aren't so excited about.
I've lost 100 pounds and kept most of that off for close to ten years now. I still struggle with my eating choices every day. My hubby has lost 200 pounds and kept it off for a year now and loves eating keto. His diet and choices are not a struggle for him now, but he was very resistant to any changes in his diet when I started (10 years ago) and was always what I considered pretty fussy. Or at least, no willingness to try new things. I got very sick a couple of years ago, my blood sugar was out of control (400 range), my hubby was facing 400 pounds, and we had to change what we were doing or we were going to die. It was that serious. It's been sooooo much easier on me now that he is buying in to the eating program.