My thinking is along the same lines. I think OP and his wife both have good arguments for making certain dishes certain ways. And indeed, it seems (to me, in my unqualified opinion) that they need to have an ongoing conversation about which dishes each wants made which way.
OP's wife is nostalgic for a certain boxed pancake mix because it reminds her of her deceased mother? Cool, that's pretty low-stakes, just make the boxed shit. But part of OP's self-care routine is cooking food from scratch, and that's important too.
OP is right that fighting over this is silly. OP is wrong that scratch-made will always be better. Oh, I'm sure it will taste better, but in the long run it will be worse for OP's marriage.
And crucially, they both need to be flexible. If OP takes pride in their cooking and the couple is having company over for brunch, then maybe leave the boxed pancake mix in the pantry and let OP wow the guests with their delicious and fluffy scratch-made pancakes. And of course, OP needs to remember that that flexibility is a two-way street.
I grew up in Honolulu, and every once in a while there would be a tsunami warning. I don't know how old I was—I would guess 6 years old, give or take a couple of years—but during one tsunami warning my parents drove up a ridge and parked on the side of the road to wait it out. We had a VW Vanagon, and I remember sitting in the van playing with toys to pass the time. At some point, a girl around my age joined me in the van. Her parents had the same idea as mine, and I guess they invited her to play with me while we all waited.
I'm in my 40s now. I still think about that girl from time to time.