Something like Guix is more in line with what people say about the potential of lisp languages.
I don't think Guix is more in line with the potential of Lisp than Emacs. Guix is a great project but it is creating a UNIX environment with Lisp, not a Lisp environment. Emacs with EXWM, Gnus, eww, pdf-tools, etc. on any UNIX clone is far closer to a Lisp environment than Guix with for example a standard Gnome installation, even despite Emacs at the end of the day still being shackled by UNIX.
Why aren't there more programs configurable in lisp dialects, or more pure lisp programs?
I mean there are lots of applications written in or configurable in Lisp, what are you looking for in particular? For example nearly all applications I use are configurable in Lisp, because most of the applications I use are Emacs or extensions there of. The only applications I have downloaded and installed (I use one of these distros which doesn't by default install X11 etc.) which aren't configurable in Lisp are texlive, mplayer, youtube-dl, and development tooling for non-lisps. Texlive could even be replaced with Pollen if I was more adventurous.