Blogging platforms that make it easier to publish and to be discoverable contribute to the problem just by making it easier to publish and to be discoverable. When writing a blog meant writing your own HTML, or at least installing and configuring some blogging software, and you’d have to write content other people linked to get a good page rank for your website, that served as a filter for low-quality content.
I’m not advocating to abolish blogging platforms, but they’ve been a double-edged sword in that way.
I was looking recently for some guides about Docker, as some parts were confusing me -- everything on the first couple of pages of Google was clearly just badly repeating the "getting started" guide, which I'd already read!