I have this argument with my wife often. I like to cook, and for me cooking is more than taking frozen meatballs and dumping them into a pan full of jar pasta sauce. I would rather make the sauce, maybe have some meatballs made in advance. My wife seems to think that pre-made stuff or mixes are the way to go. I would rather just make pancakes scratch, which isn’t hard, where she would rather I just open the mix, add water, and make the food. But I do agree that having a frozen lasagna is better than taking the full effort when I just want to get dinner going. So where are your eat the pre-made vs make it from scratch?
Your way is always going to be significantly healthier. Among other issues I think you’ll find eating food your wife prefers puts you both well over the recommended sodium intake for a day. This is likely to shorten your life due to heart health.
The healthiest way to shop is to stick to the outside of the super market and skip the packaged foods in the middle.
Nostalgia or not, eating packaged food to often is very unhealthy. Maybe broach it with your wife and ask her if you can satiate her nostalgia in moderation. Having something she really loves out of a package only once or twice a week.