I ended up getting gifted a set by America's Test Kitchen. Their website is pretty bad, they actually have some fundamental books - chicken dishes, side dishes, fish dishes, etc with hundreds of recipes in each. Most recipes describe a couple of failed attempts, the reasons they failed, and why the final recipe works. Great for learning. Most are simple recipes that don't take a bunch of ingredients.

My cooking just accidentally went up a couple of notches after cooking a couple dozen recipes out of the books, and paying attention to their failure descriptions. Pretty great way to passively learn!