Perhaps you weren't around at the peak of blogging era when all the gurus usually running self-help blogs were preaching that writing style to aspiring bloggers. It stuck around and still is dominant in blogging - and for good reasons for certain audience.

Information examples from more popular blogs:

https://neilpatel.com/blog/write-copy-like-apple/ https://copyblogger.com/short-guide-to-good-copy/