I came here to say something similar. You're right to point out baking powder, because it's a mess. Think it's all the same chemically? Nope. Different brands use very different chemicals that can affect lift, and it can vary over time for the same brand.

Just about everything is like that. Whole wheat flour? Different bran and gluten percentages create really different loaves.

Pretending weights will solve everything is nonsense too. If humidity affects mass per volume, it's going to affect chemical identity per mass too.

Finally, everyone has different tastes. You might like a finer crumb to your bread; your spouse might like it more holely.

Recipes are like guidelines. Always. Experience matters because it reflects knowledge of how variations on the recipe matter.

Finally, if there's one thing I've learned, it's that a lot of things in cooking get passed down as critical when they're not, or even worse, are detrimental. This goes for traditional knowledge handed down, as well as half-baked "scientific" approaches to recipe development that are bad science and driven by a desire to establish authority above all.