Is anyone here daily driving an obscure OS like HaikuOS, ReactOS, MorphOS, etc?

I do! I daily drive SourceMage Linux. I found it while I was spelunking distrowatch (along with its brother, lunar linux - they both branched from sorceror back in the day) I ended up having so much fun tinkering with it I ended up writing some spells (packages) for it and ended up getting pulled on as a spell maintainer :) I don't really have a use-case for it; Before it, I was hopping between arch and void linux. I do really enjoy the freedom I have though with SMGL - it's a source-based distro, so it's similar to Gentoo in a sense. Plus I just enjoy having a deeper look into things! I break stuff often and sometimes spells don't install correctly/have problems but solving those issues just makes it that much more fun :) I do highly recommend it for anyone looking into trying out a source-based distro and Gentoo doesn't interest them. (we're #sourcemage on libre.chat IRC, come say hi if you'd like, or if you need help installing, i'll happily walk anyone through the process!)