Because for those of us that are not, WordPress is a pretty easy and pretty capable way to self host something. Without it, lots more stuff would be centralized with Big Tech.
*Static Site Generator
They are not web programmers maybe not even in devops. So It is easier to just buy basic shared hosting wit button 'install wordpress' in hosting-admin.
Statically generated site would be better (especially for readers of the site) but they still need some CMS.
I mean, I liked Drupal, still do, but the business for custom Drupal sites dried up and moved onto WordPress with (insert builder of choice here). Teaching anything on Drupal was like pulling teeth, even in the D7 and D8+ eras. And I'm not aware of any demand for Backdrop / Concrete5 / whatever sites. WordPress even ate up whatever demand there was for Magento (good riddance IMO).
Everyone moved to WordPress because it's easy to teach clients on, the dev costs are reasonable, and there's a really good plugin ecosystem to counter the platform's faults. You can absolutely build unique sites on WordPress and lock them down too.
If WordPress dies, everyone moves to SquareSpace (which is proprietary) or socials (in other words, doesn't have a web presence).
The community was significantly smaller, but many of the plugins that existed were very well maintained, there was a small but healthy set of developers with paid plugins.
I don't want anything to do with that industry anymore, whenever I want to put up a little site I just use a static site generator (hugo). I think there is an interesting potential market for a wp admin like UI that could be used to create hugo posts/etc and manage the theming configuration. Then you click publish, it fires off a hugo container that generates the static site and updates the host... maybe such a thing exists.
The track record of "modern" would suggest Wordpress is the second coming of Jesus, so no thanks. Wordpress is fine compared to "modern" software.