Ask HN: When does it matter to analyse competition and what tool to use?

Before starting to work on a new project, I would normally try to map a competitive landscape, using google search, Crunchbase among others.

However, I discover most of the relevant competitors after starting to work on the actual project as people will start pointing to this or that competitor, which is often very useful.

Have you felt this problem before? And how do you go about researching the competitive landscape?

Thanks a ton for sharing your inputs