My impression of ZSH after fish is "ok this made for a really annoying couple of hours to set things up, but now I'll never have an incompatibility hassle again!"
When I was in school and working on my own stuff I liked using fringe shells like xonsh and fish, but working in teams I feel like I need a pretty significant productivity increase to justify using a different tool than everybody else.
Unless you source a lot of shared scripts why would it matter what shell you use interactively? You can install fish and bash side by side and use one in your terminal and one for scripting.
I share a lot of snippets and commands with members of the team, write a lot of bash (which I like to debug in interactive mode), and often follow or produce documented procedures in interactive shell (not quite repetitive enough or frequent enough to bother scripting).
