From the whole blog post, the thing that caught my eye was the side remark regarding SPAs vs MPAs. It was one of those things that people don't tend to think about it but once someone touches on the subject, the problem become obvious. It seems that modern javascript frameworks focus on SPAs and try to shoehorn the concept everywhere, even when it clearly does not fit. Things reached a point where rewriting browser history to get that SPA to look like a MPA is now a basic feature of multiple pages, and it rarely works well.
Perhaps it's too extreme to claim that MPAs are the future, but indeed there are a ton of webapps that are SPAs piling on complexity just to masquerade as MPAs.
I don't see why you should be concerned, except that no professional software developer is limited to use one specific programming language.
Even if you pay attention to the disaster prophets in the crowd, which are mainly comprised of fanboys implicitly and explicitly promoting their pet language/frameworks, C++ dominates all aspects of the computing ecosystem, which means that in the very least the whole world needs to maintain existing C++ projects to continue to work. See COBOL for reference.