Programmers adding features to languages the same way horror movie characters decide on entering an abandoned shack in the woods.

No. f-strings are an awful idea. And combining them with r-strings is yet another awful idea. Please, never do that.

I'm also not a big fan of extended / verbose regular expressions because it creates ambiguity in interpretation (a slightly different language to define regular expressions). It's a bad solution to the problem of building longer expressions, which should've been addressed in a different way: by making the language of regular expressions more modular, not through allowing more hard-to-interpret language details.