Too many startups attack the low-hanging fruit first because it is easy to show they are making progress. However, this is false progress. It is better to tackle the hard tasks first because if you can’t solve them, there is no point in doing the rest. This concept is known as the Monkey and the Pedestal. For more details, check out this post; https://stevebizblog.com/why-is-the-monkey-and-the-pedestal-story-so-important/
