Home cooking is an improvised activity, primarily because its so lenient in what it'll accept. Of course, maybe the french will tell you otherwise, but most food doesn't come with any intent to be 100% reproducible (and it'd be extremely boring if it were), or "designed". They come out leniently tasty, and they look good leniently.
Until brown? Until it looks like a good shade of brown. Until ready? Until it feels like its ready. To taste? Until its tasty.
Its imprecise, because its an ancient activity. You do what seems like a good idea, and don't do it next time if it fails. Its a game where losing is kinda fun (unless you're "designing" food, which I have nothing to say about)
I recognize that some people enjoy the art of cooking, but I personally don't. I cook to make food so I can survive. Perhaps I just haven't found the right cook books for my demographic.
It's actually incredibly frustrating when trying to follow a cook book _because_ they're often so vague. Even things like "4 cloves of garlic" are nerve-wracking because I have no idea how big the average garlic clove is, whether mine is above or below that, how much that matters, in what ways that will affect the taste, how I should accommodate for more/less garlic later, and so on. Garlic's an easy example, but this frustration applies to almost every ingredient -- especially when they're "to taste" or "until brown" (how brown?) or "until ready" and so on.
Give me 600g, give me "stir for 2 seconds", give me detail! If I wanted to go off-book, I wouldn't be using a recipe!