StackOverflow surveys, while interesting, are probably meaningless because they suffer from selection bias. Even so, I would guess that F# developers are very well paid, like other developers of FP languages, but it's probably not because they work with F#. The causality is likely reversed - good developers that tend to be well paid are also the kind of people naturally interested in expanding their skill set, hence interested in FP languages.
Nothing screams spam more than usage of a hot keyword like "functional programming" while leaving hints that you don't understand what you're talking about. I would expect an article that reads like a marketing brochure to at least make a short attempt at explaining what functional programming is. If you copy/paste testimonials from fsharp.org/testimonials, you could also copy/paste from Wikipedia. But then, their own course named "Functional Programming" doesn't seem to have anything to do with actual functional programming: https://fsharp.tv/courses/functional-programming/