WordPress dominance of the web has certainly peaked, but history indicates there will be several years in which to continue to extract comfortable profits while riding it down. e.g. Oracle, a database that almost no business has actually needed in decades.
I'm not convinced that sort of legacy lock in exists in the web space. It moves fast and its value is in the content. In the age of AI, migrating that data makes it trivial to move away from a risky platform. I cut my development teeth on WP and managed some fairly large sites. There are far more interesting and well developed alternatives out there.
Sure, but, even with AI and the technical competence to steer it, it's still a pretty big lift to switch from, e.g. WordPress with billing and various other stuff to some ad hoc other thing. Even when I decided I was done with managing content in WordPress and moved it out to a Hugo static site for my company website, I still kept the commerce stuff in WordPress just because it works and we know it works from a decade or so of operation.
I'm certainly not deploying new WordPress sites, partly because of how weird and hostile Mullenweg has made the WordPress ecosystem for no good reason. I don't even necessarily disagree with the sentiments behind his words and actions, but the methods and how far it's gone in terms of lawfare is just silly and destructive.
Anyway, they won't get decades like Oracle has gotten. But, they've got a few years of comfy margins ahead if they don't blow it up too badly.
They'll continue to have plenty of existing passive revenue as long as WooCommerce users continue to use Stripe, and large enterprises continue to buy in to WP.com VIP.
This rings true to me. I am looking at setting up my own online store, and if you sell (legal!) stuff which Shopify Payments disallows, but Stripe does allow, you end up looking at WooCommerce (a very popular WordPress plugin) pretty fast.