I have a similar idea. I've been working on a design for a Common Lisp-based desktop environment that can run on top of Linux and the BSDs. It's inspired by the Lisp machines of old and OpenDoc, an API for building component-based software that was championed by Apple and IBM back in the 1990s before Steve Jobs returned. I haven't started writing any code yet, partly because I've been learning X programming and other parts of the graphics stack like Cairo and Pango.
I have some more ideas at http://mmcthrow-musings.blogspot.com/2020/04/a-proposal-for-..., though I wrote this before I committed to using Common Lisp (I talk about using GNUstep near the end of the document, but I've since ruled it out due to the difficulty of finding modern Objective-C bindings for SBCL that work with GNUstep).
I have some more ideas at http://mmcthrow-musings.blogspot.com/2020/04/a-proposal-for-..., though I wrote this before I committed to using Common Lisp (I talk about using GNUstep near the end of the document, but I've since ruled it out due to the difficulty of finding modern Objective-C bindings for SBCL that work with GNUstep).