I personally have not used it but the syntax looks nice enough - but it still looks interpreted, not compiled - I can't stress how important it is that with Powershell, you can just straight up write PS and it'll still run at a decent speed.
In my experience, half the CLI utils used by bash scripters do things you could do with Bash, but they're much faster on account of being written in C, but you have to suffer through learning their quirks.
An example I remember was when I needed to parse tens of gigs of JSON into a pandas dataframe (CSV on disk) - the python and bash versions ran at like 2-3MB/s, while the Powershell version did 50-100MB (which is still not great, but certainly good enough for what we did)
I'm clearly not as experienced as you with powershell, but I have used both nushell and powershell and like both. I definitely prefer nushells syntax. I personally haven't come across anything that was significantly slower with nushell over powershell. I my experience nushells out of the box functionality far out stripes powershells and it's object model is much easier to reason about.
I see a bunch of folks recommending this, but I have to wonder where this game ends. Always one more new tweak to the local environment. Just one more dotfile, bro, I promise this time your environment will be perfect. Just one more little supply-chain-attack vulnerable component running with the same access as you, the user. But look, you can save 20 microseconds on your shell history search or whatever!
Is there some actual reason to use this? I got sold on `zsh` as it became the standard on the Mac and was packaged by all major distros, but honestly I'm still fine with just plain bash, though I miss the pretty prompts. What is one really getting out of nushell / ion / whatever new tweaked out shell comes out next week?
Why should the game end at all? Why shouldn't people continue developing better and better shells that people can use to interact with their computer, or maybe different ones for different use cases? Supply-chain attacks are bad and worth mitigating for any kind of software, not just your shell; but the possibility of such an attack doesn't mean it's inherently unwise to try out new pieces of software. Saving time on your shell history search is good and declaring it unimportant merely because the amount of time saved sounds small, is how we wind up after many iterations with software that is noticeably laggy to the end user. But the real value of new shells I think is the new features you didn't know you would find useful at the time.
A: ...in many ways Powershell is stil king of the shell game [but]...
B: Have you tried nushell?
Anyway... nushell is more similar to Powershell (but AFAIK there is no JIT). My default is zsh (as you have mantioned, because of mac) but I use nushell for few things - it is pretty different from bash/zsh/ion/fish. It is more like data pipeline.