i think the best answer i thought as to why the list of craftable food is do boring and mainly steak and soup, is its easy. easy for the player character to craft when all you need is one or 2 ingredients, easier for the devs to not have to make recipes and new models for different foods.
even so they really skip out on something vitally important to world building. theres a ton of dishes you can make using the ingredients in fnv and fo4! but they arent there!! even with a 200 year difference, i dont think it would be so much as everyone just went back to eating meat on a stick again, itd be more like people find innovative ways to flavor meats considering a lot of it probably tastes horrible.
its trivial and its extra work that the average gamer wouldnt care about, but food is a really important tie into people’s lives so if you want to make a setting where people feel like they are living and thriving, they’d have more recipes past meat on a stick and meat in a broth.