Steam.app would like to receive keystrokes from any application I just installed a new version of Steam on macOS Catalina 10.15 (19A602) and got this unexpected request:


  Keystroke Receiving
  
  Steam.app would like to receive keystrokes from any application




I hit Deny since I can't see any good reason why Steam should need this. I can't find any answers, having looked at a thread on Reddit and Apple Support forums. This security article from Sophos, Synthetic clicks and the macOS flaw Apple can’t seem to fix seems to be related.

Why would Steam need this?
Under Catalina's security model, Apps are supposed to operate isolated
  from everything else, including your data. If they want to use your
  data or a service from another App, they must ask you for permission
  to do so.


Source.

This seems reasonable given the message in the dialog box, however I can find no direct information directly from Apple so please take it under advisement until it can be confirmed.