openssh has been an optional windows component for... almost a decade now? including the server, so you can ssh into powershell as easily as into any unix-like. (last time I set it up there was some fiddling with file permissions required for key auth to work, but it does work.)
OpenSSH on Windows is great for the odd connection and SFTP session, but I still feel strongly that any serious usage should just stick with PuTTY and WinSCP. The GUI capabilities these provide are what Windows users are used to. The only benefit of built-in SSH is if you're working with some minimal image stuff, like Windows Server Core or Tiny11. IMHO.