I still write a lot but mostly have other outlets than my personal blog.
The Oatmeal summed what occurred pretty well
I guess it depends of your definition of blog, but I remember Fotolog being incredibly popular circa 2006 even when compared to mainstream social networks. While Wikipedia says it's a social network, I recall it was used mostly for blogging (not so much for social interaction).
And IIRC, when Google acquired Blogger (2003) blogging was not exactly a obscure thing, although I don't think I knew anyone with a personal blog back then.
Nowadays most blogs are commercial entities ("Websites") that cover a fairly narrow topics like EVs or Electric Scooters or Photography reviews but personal blogs and websites still exist they just don't fit into the microblogging narrative and aren't prioritized. People who want to be "influencers" are probably not going to start a blog as the immediate reach of a blog is measured in hundreds or low thousands of hits per month.