I sometimes feel like zsh is one of those things along with tiling WMs that people spend so much time dinking around with the configuration of that any gain in productivity is negated
I don’t spend hours configuring it: I’ve just put my settings and plugins in a git repo and now I have an identical environment that’s fine-tuned for my uses on any computer I use (but then I don’t use any tiling WM). Clearly for me the initial investment of reading zsh’s documentation thoroughly and playing with a bunch of plugins for an afternoon or two was worth it.
Also remember that productivity is difficult to attribute to a single factor. Just having a more pleasant shell helps staying focused and motivated, even though the settings themselves do not improve efficiency directly.
