Boomers came up as fast food franchises and convenience foods began to dominate. The equal rights movement meant more women in the workplace and less in the kitchen and instead of spreading the burden, capitalism filled in the gaps.

Another explanation is that American cuisine got wrecked by the Great Depression. Everything that had flavor was expensive. People's inability to purchase and make certain foods stopped generational transfer of knowledge on how to make certain things. Thankfully, after several generations it's finally recovering.

"Ethnic" food (non European) wasn't as affected as much.

I heard an interview about a book on it a few years ago but now I can't find it.

Because they did cook well at one point. It took hours, it involved a lot of cleanup, and 4 year old you whined and complained for some chicken nuggets and the fucking candy bar your aunt gave you without talking to your parents first.

So they gave up. The tantrums, the rejection, the effort. None of it was worth it. Like pretty much every skill in life it atrophied.

Too many people order shitty delivery so that they can save 15 minutes cooking while spending 3 times more