I switched from Zsh to Nushell almost two years ago and I have never looked back. If you need POSIX compliance, Nushell is a no go. But it sounds like your real problem was just that Zsh was familiar whereas fish was not. Nushell strikes the perfect balance of offering the commands you’re used to but letting everything just make intuitive sense. Plus, its help command is so far above and beyond other shells. I rarely need to open the Nushell docs (even though they’re really good), and I never have to go the community (even though it’s awesome), because I can figure pretty much everything out just from interacting help within the terminal.