I see a lot of cases of people saying estimation is impossible, which upon closer inspection turn out to be a different argument: &quot;perfect foresight is impossible&quot;.<p>The Nirvana Fallacy, in other words. Because it&#x27;s not perfect, it&#x27;s worthless.<p>Of <i>course</i> perfect estimates are impossible. You need to make them anyhow. And if you don&#x27;t make them explicitly, you&#x27;ll make them implicitly, and they&#x27;ll be worse.