To say that it's missing features is to imply that they could add features and then it would be as good. That's not the case I see, as a shell is little without the surrounding ecosystem, and Windows doesn't have it.

PowerShell is missing QWAN; The linux CLI is the same if you boot to it or boot to a GUI and open a terminal, or SSH in. It has a wide ecosystem of meta-apps which aid using the CLI such as screen and less, and it's been built up over the years with bash/readline keyboard shortcuts. Not to mention that lots of nix programs are CLI programs with GUI wrappers, or configured with text files you can edit in emacs/vim.

The Windows command line window is all there is (you can't boot to 'DOS' anymore, or SSH in without third party software - and if you do it's a different kind of experience). There's nothing much to do as most programs aren't CLI programs and aren't configured with text files and aren't scriptable and you don't really want to poke around in the registry if you have to be typing "HKLM\Software\Microsoft\Windows\CurrentVersion\Policies\..." or whatever. There are no emacs keyboard shortcuts and everything is shoved in folders with long names and capital letters and spaces and it's just not as good*. On top of that, PowerShell is a misleading name - since it's not really a shell, it's more like irb or the Python interactive interpreter. Sure you can "change directories" and such, but it's not really a bash competitor, not a shell in that sense.

But on paper, feature for feature? Who knows, they're probably quite close...