So I have the ability to reproduce the results from a batch if I want to? Throwing things together without measuring will make beer, sure, but good luck ever making that same batch of beer again if you love it without recording your numbers and process.....
Actually that was supposed to be a joke. I guess I forgot to wink.
Since you brought it up though, I do remake favorite recipes without measuring gravity. I all but stopped checking because my process was dialed in enough to hit the numbers every time. If my hydrometer was to break, I don't think I'd replace it. I certainly don't need one for repeatability. Of course there's nothing wrong with those that like to measure and record every detail. I can definitely see where that's part of the fun of this hobby.