My grandma's 1975 Joy of Cooking has notes in the margin about oven rack position. That little detail (which most online recipes skip) changes how heat hits your baked goods. I bet the real issue is that old books assumed you'd read the whole chapter on basics first. Online, each recipe stands alone, so they don't teach you why creaming butter matters. Without that foundation, tiny changes in temp or mix time seem random when they're actually key. So maybe it's less about testing and more about missing context in digital recipes.

Still scroll in bed sometimes... never noticed a difference though.