> It's pretty hard. There are a ton of people who can make a cake from a box, but not "from scratch".

I don't buy it. A basic cake recipe is simple measuring (with enough tolerance that anyone can do it), mixing and pouring. No special skills required.

> Doing it yourself means the ratio is never quite the same as last time, even if you try really hard.

Ok, for sufficiently small values of "not quite the same", but so what? There's going to be more significant differences in your eating experience than the cake having a tiny bit more sugar or whatever. And companies change their mix all the time too.