As a user and fan of fish, I hesitate to recommend it to people because support and availability for fish is just not where other POSIX shells are. It's gotten better with time, but VSCode extensions still don't setup conda properly in my fish shell.
I still find myself frequently dropping into bash everywhere, but I really want fish to succeed. It's a huge breath of fresh air coming from POSIX shell syntax, and I've really enjoyed automating busy work with fish. I really ought to submit PRs when I have the chance.
There’s also the problem of what is installed universally, and having to know both bash and fish.
If all you ever have to deal with is a single CLI on a single instance, and you never ever have to deal with any other system in CLI mode, then I’m sure that switching to a more modern shell can be useful and a good thing.
Until you do have to deal with a different system that has a different shell installed by default.
Give me a shell that is literally 10x better than bash, and is also installed universally, and I’ll make the switch. Until then.....