The short answer is 'No. Yes. Maybe.' It's your preference balanced against your time constraints.
I'll use my silly little blog 'Blue Night' as an example. I started it five years ago because I was having a romance book published by a small press publisher, and they suggested It Would Be A Good Idea.
It was, but not necessarily for that book. I got into the habit of essays and journaling in high school, and blogging seemed a fun extension. In any given month, my blog might have a bit of personal writing promotion, a review of an old favorite book or new book I love, a sociopolitical rant, and some showcases of my new art, or reviews/analysis of other people's art (things I adore). I rarely blog more than once or twice a week, and not on a schedule. My 'real writing' has to come first, of course.
Is this a workable 'platform'? Don't know, don't care. Between thirteen and one hundred people read it each week. It's a showcase of most of the things that make me tick.