If I have to switch shells all the time when another shell, zsh has the same functionality as fish, without the switching around, I'll use that. Not to mention fish causes flatpak to not add Flatpaks to the app menu until restart. Environment variable messes. If I have to install a bunch of other stuff to make fish work, vs make zsh work more nicely, I'll pick the 2nd one.
DOSBox-X?