I think the secret to getting you blog indexed in Google back then was FeedBurner. At some point after the acquisition Google merged FeedBurner’s crawler into you own with the consequence that if you “burned” a feed and had one email subscriber Google was forced to index anything in your RSS feed almost immediately.
Somehow Google found WordPress blogs highly attractive, probably because of heuristics that they put in…. Cause web crawling and web search are all about heuristics. On some level tracking changes to a WordPress is a hot mess because it has numerous reverse chronologically sorted pages that all update when you add a blog post which makes more work for the crawler but also makes the site look more dynamic than it really is.
The usual reason I hear “blogging is dead” is that Google isn’t sending traffic, it could be Google doesn’t have heuristics to support modern blogging platforms (say Hugo) that it did. Maybe Jamstack = Invisibility.