OP here. What was telling to me is that even new media websites are using other CMSs or building something of their own these days. WordPress was almost synony

OP here. What was telling to me is that even new media websites are using other CMSs or building something of their own these days. WordPress was almost synonymous with the online news media for a time. This is exactly the area where you need multiple authors, taxonomy, and other things you mentioned. WordPress itself pushed heavily into ecommerce, because it was a more promising area. But at the end of the day, the fact both Automattic and WP Engine earn enough money from enterprise orgs doesn't mean the tech situation here is too different from IBM. Yes, it's big. Yes, lots of people use it. Will it define anything in the future of the web? Not really.