Look, I'm not saying C is important nor that people aren't using it but... Let me ask you one thing, if you look at the majority of the web (not specific cases) you'll find that 76% of it is PHP. Furthermore if you think that everyone is moving to mobile apps you'll get a mix of Java/Kotlin, Swift and a very strong move to towards cross-platform stuff that is, in most cases, based on Javascript. To make things worse bootcamps for wanna be devs have been teaching node as a valid backend solution for quite a while now. We see startups going that route and things going perfectly well.

Since we've that huge market for higher level that run perfectly well on ARM do you really thing that stuff made in C really dictates the future of the market? The "issue" I see with the link you've provided is simple: nobody is developing "run of the mill" solutions with C anymore like we used to and those are the solutions that have the numbers to move the market. Nowadays C is operating systems, libraries for higher level languages, engines such as the JS V8, a ton of IoT devices (that ironically are ARM), low level electronics, industrial automation and financial use cases where performance is really important.

C is going to stay on specific places but nobody develops websites, desktop and mobile applications with hence my simplistic "the software development market evolved from C to very high language languages such as Javascript/Typescript" conclusion.

The market is moved by the large masses and the masses use technologies that are not bound anymore to architectures like other used to be.