One big hit for me was having to create an entirely new set of recipes when I cut out meat from my diet. It got really hard because plant protein is way different from animal protein. The processed vegetarian stuff is insanely expensive too.
Modding those recipes to replace the dependency on heavily-processed ingredients with the fresh, less-processed comparables readily available today often produces good results, though it does take more time.
[1] - https://archive.org/details/cbk?and%5B%5D=year%3A%221950%22&...
I am an accomplished cook and I have a lot of recipes passed down a century or more first-hand. Many have the property I described. I know many other people with similar family recipes.
Just because you’ve never heard of it doesn’t mean it doesn’t exist.
Beyond that, what do you think is more representative of recipes of the past? A selection of hundreds of recipe books with thousands of recipes, or the family recipes of yourself and some acquaintances?