The debate between mouse and keyboard versus controller for FPS titles has been ongoing for years due to newer FPS titles granting controller players greater aim assist. However, it appears that Steam Controller configs are giving controller players another leg up in Apex Legends.
By binding keyboard inputs onto your controller with Steam Controller configs, you can map the WASD movement keys onto a controller. While this seems insignificant since controller players can move just fine without this, the ability to map those keys onto a controller gives much easier access to tap strafe on a controller.
While this trend is unlikely to become common among controller players due to how arbitrary it is to setup, it does contribute to the ongoing debate on how best to balance controllers against the traditional mouse and keyboard. Due to the mouse's precise and fast tracking, mouse and keyboard players have historically had a giant advantage when playing against controller players.
However, developers have recently been adding much greater aim assist to their FPS games which attempts to put controller players on a more even playing field. This balance is tricky, though, and striking a balance where controller players have a chance while not receiving major advantages has been near impossible for the FPS community. While these two control schemes continue to cause controversy as players pick sides, more of these niche edge cases will continue to reveal themselves.