According to this data (the same data referenced by WordPress marketing blog posts[1], if it's legit enough for them it's legit enough for me) WordPress usage across the web stopped growing almost all at once in 2021, with the beginning of a decline this year.
You can see an increase of other contenders (Shopify, for example) but of note is also None, which is probably related to how LLMs have been making it incredibly easy to deliver a website even without a CMS.
* WordPress remains roughly unchanged over the past five years, until the final datum which is lower than the flat trend.
* None had been decreasing but over the current year to date has increased sharply, correlating with the LLM trend and subjective notions of LLMs having "finally gotten good" for coding, though the trend is rather short.
* Over previous years, Shopify and Wix began to take increasing amounts of market share from WordPress as well as legacy competitors.
Because this chart shows proportions of the web rather than a total number of websites, and by virtue of remaining at the same proportion while the denominator increases, we know that the number of WordPress sites on the web is still increasing even if this is not clearly depicted by the chart. But I would argue the more important story is that WordPress is no longer eating the web as much as it is just consistent, and I think this shows that WordPress is now genuinely a little bit vulnerable as a singular platform choice to learn.
I don't disagree with the fact you had raised about fancy custom React SPA style apps being fairly rare in quantity across the web when so much of the web runs on whatever offering has a decent CMS and isn't too hard to deploy. And WordPress is still a great choice to learn today for those looking to make good money doing web dev, especially in freelance, marketing, e-commerce, etc.
But WordPress may actually finally be on the decline after holding steady after so many years, and having seen this data I would personally have come to a different conclusion than the one your post did.
Maybe I would have said something along the lines of "Despite the constant rumors of the death of PHP, WordPress has grown to serve nearly a majority of the websites on the internet and has held a steady chunk of the market for the last five years. Learning to use it is still many people's best chance at success in web development, even as other trendy technologies appear on the market. Even if WordPress were to significantly decline in popularity, a very large portion of the market for web development would continue to belong to those who chose to learn WordPress." I feel like that is still in the spirit of what your post intended, but with slightly closer alignment to some sort of data.