Not that it’s a particularly compelling feature on Linux with the standard offering, but it’s a good option for cross platform scripts at times, particularly running in docker.
I mean, if I want something that can run on as many platforms as possible without a prior installation, I stick as closely as I can to posix sh. If I want something more flexible that can run consistently, but may require an installation beforehand, I use python. I don’t really see what niche PowerShell would fill for me.
It doesn't have to fill a niche for you. Before cross-platform PowerShell I certainly used Python for some of those kinds of scripts.
I think a lot of it gets down to ergonomics/aesthetics to decide if you find a useful niche for PowerShell for yourself. Python's os module is powerful and lets you run/chain almost any native commands and shell operations you want to spawn, but it is still a very different API and abstraction with different ergonomics and aesthetics than shell-style pipes and redirects.
PowerShell gives you that focus on shell-like pipes/redirects, but then gives you some Python-like power on top of that to also work with the outputs of some commands as objects in a scripting environment. There's a lot of interesting value to comparing/contrasting PowerShell and Python and if you are happy with Python maybe there isn't a big reason to learn PowerShell. PowerShell is there for when you are doing a lot of shell-like processing pipelines and want to write them as such, but have some of that power of a language like Python behind it. It's a lot more powerful than posix sh and it is similarly but differently powerful to Python but it starts from a REPL that looks/acts more like posix sh. I don't know if you have a need for that niche yourself, but I find it useful for that.
Seems worth investing a lot time into given Microsoft’s history of not rug pulling developers.