The OpenPuck project allows the Steam Controller to emulate console controls, among other uses

A work in progress, but a very intriguing one.
XDA Developers on MSN

This open-source puck lets you use your Steam Controller on Xbox, Switch, and PlayStation consoles

It's cheap to build, too.
Engadget

Valve Steam Controller review: A gamepad in search of a console

We may receive a commission on purchases made from links. Don't mistake the Steam Controller for a PC controller. Even though its main function is to play PC games, Valve's new gamepad communicates ...
PCGamesN

Steam Controller review - another essential gaming PC hardware addition from Valve

Most of the hype surrounding the announcement of Valve's recent trio of new hardware was focused on its Steam Machine mini gaming PC, as folks hoped and assumed it would be as aggressively priced as ...