I guess the corollary to this could be “don’t use a compass when the precision of a GPS is needed”. In fact, the main point is to use the best tool for the job at the time. If you need to move fast and just want to make sure you’re directionally correct, then a compass is perfect. With plus/minus a few degrees of precision, you can quickly set off in the right general direction. In fact, I wrote an article on this exact topic titled “An Unfair Advantage All Startups Have Against Big Companies“. Same for things like estimating your TAM/SAM market size (does it matter if it’s $3.2B versus $3.3B?), estimating salaries for new hires over the coming year and the like.
The analogy of using a compass is ideal for times when speed and flexibility are more important than precision. In other words, make sure to use a GPS instead for things like revenue recognition and your investor capitalization table – where precision is mandatory.