Musl mostly works. I had more trouble taking out bash, because of all the random bashisms.

On my system I forked dash to create 'bolderdash.' Right now it's pretty basic, I have changed little (just did some cleanup), but I did add in a couple tweaks to enhance bash compatibility. The goal is a complete refactor, more compatibility with bash, and much better command line editing etc, while still remaining sleek and lightweight.

I'm also forking musl to create 'powrlibc.' It will have a lot better glibc compatibility, as well as better optimizations and some other improvements.

Switching out glibc is pretty easy compared to systemd. That's the thing peoplle don't get. systemd is seriously insidius, like a virus.

I've personally run Gentoo with OpenRC+glibc and OpenRC+musl on my laptop. I assure you ditching systemd was easier than ditching glibc. The OpenRC system mostly just works (tbh thanks to a lot of great work by Gentoo devs). The musl system required probably a couple dozen patches to various packages to get a basic fully working desktop (most of which were relatively straightforward, but still needed manual intervention).