It’s of course true that you should be capable of scheduling things for the future, but I suspect that for the vast majority of people (myself included) “do stuff now, not later” is the directionally correct advice.
In an example of synchronicity just today I was pondering how easily the virtue of patience quickly becomes the vice of procrastination:
It’s one of those irregular verbs: I patiently wait, you procrastinate, he impedes progress.
And so the earworm Gwen Stefani song "What you waiting for?" popped into my head which more or less is the same question: what is so much more optimal about doing it later - what conditions aren't right? But I think I've had a very different realization to you. Because in my case the action in question involved money, money I don't have, money I don't expect to find any time soon.
This, of course, prompts a totally different question: "What must I do instead, and now?" which is annoying in that it's no closer to, you know, taking action. But it's also exciting in that I've discovered that I was using the totally wrong frame to approach the issue.
In my case I wasn't procrastinating, procrastination is when you have the ability to do something and a sense that it is beneficial or obligatory but not the will to do it. In my case I had the will but not the means. Never the less, a valuable question to ask - if not now, when - because I didn't realize that until I asked it.
Sometimes "Why not now?" is the wrong question, it should be "So, what else now?" - and sometimes, it is the right question and the answer is "Do it".
One thing that stuck with me after having it read somewhere, probably on lesswrong, a few years ago is the framing: "does future-you have a comparative advantage to do the thing? Otherwise you may just as well do it now". Which maybe doesn't quite capture your cooking counter-example, but it seems like a useful way to address procrastination nonetheless.
Hillel... would say: "If I am not for me, who will be for me? And If I am just for myself, what am I? And if not now, when?"
That last question has usually been interpreted as a rhetorical one. If you're not going to do it now, you'll never get around to it!
But this is clearly a bad principle to live by. If you start cooking too early, the food will be cold when you want to eat it. If you pick a fruit before it's ripe it will be sour. When you are exhausted the quality of your work goes down. And when you have many things to do, you have to prioritise which comes first.
There is a season and a time for everything...
Perhaps we would do better interpreting it literally. It's fine to push things off, but first you must answer the question: "When?". At what point in time, or under which change in circumstances, will you take this action? If you have a good answer to this, all is fine, but if you don't it's likely you are just pointlessly procrastinating, and the job will never be done.