Imagine that you have a niche with which you work or just want to enter it, and it already has leaders. An indicator of the keyword difficulty will also help here. In this situation, you can use the experience of competitors, their best practices and do better!
Unfortunately, in all existing services for finding competitors, there is no way to see the Keyword Difficulty indicator in the competitors report. As a result, to check a niche and obtain data for analysis of competitors, you need to do a lot of routine work.
Therefore, it is better to use the API.