I love Fish. I'm likely not their target audience.
I've been using it for years. Since the early days in 1.x land for sure. The homepage has never changed and I still laugh at the tagline. I find it's auto-completion, history and niceties indispensable. I'm the person who asks you what the command is to rerun the tests. With Fish I never have to ask you again. I just remember part of it, and suddenly I've got it.
I find its scripting language much simpler to follow than bash. I don't have a lot of scripts, but the ones I do are easy to manage. The only hiccup I get into is when I have to look up something on stack exchange, and of course the example is in Bash. These days though, with Bass and fisherman and so many other tools, i have options.
Years ago I would explain to other code friendly designers, I'm weird, don't use this stuff. Go grab zsh. Lately though it's gotten very friendly. Really the only downside for a light scripter like myself is that need to convert bash examples to fish problem. Beyond that I feel it's actually a much nicer shell for new to terminal folks.
Anyways, just an anecdote to add to the pile. Thank you to the devs that have supported it over the years.