But if you're going to dive deep on any of them, bash has a pretty unique and strong argument for being quite likely to be available on most of the machines you work with on a day to day basis.
The servers I use do not have bash installed by default.
The only time I use it is when I am forced to by an installation script.
I install bash on an as needed basis, and when I'm done using it, I uninstall it. I just have no need for it otherwise.
What is the shell on Android? Is it bash?
Many servers don't have bash installed as part of their base distribution, but if they're going to have another shell already installed it's much more likely to be bash than zsh.