Powershell isn't competing with bash, it's competing with Python. So then, how does it compare against Python? While plenty of small scripts are still done with bash, I think Python is pretty common for serious production needs. I use it for virtually all scripting these days.
I had a recent experience where a developer spent a day and couldn't get Powershell's webrequest library to do what he wanted. I was able to accomplish the goal in 15 minutes with Python on a Debian system.