The Jackbox Megapicker launcher has been corrupting Steam Decks, but a new hotfix was released that temporarily fixes this.
The Jackbox Megapicker was corrupting SteamOS and forcing people to reinstall the entire OS. It's been fixed with a hot fix for now, but probably safest to avoid it until they get this all sorted out.
What worries me is : can a bad actor reproduce whatever bug was corrupting SteamOS, and publish games on the storefront with the sole intent to mess with people?
The main thing that a bad actor would gain is "being kicked off of the steam store". The bigger threat would be if Gabe figures out which is the bad actor's main account. Losing all their games would be pretty big blowback for such an attacker.
The problem is that SteamOS doesn't have a whole lot of boot options besides "start up directly into Game Mode successfully". If Steam chokes while ingesting any of its config or any metadata in your library, that's the end of it. You can hold a button to wipe everything (the Playstation solution), or you can figure out how to boot a live-iso and fix "the problem". Not everybody has the skills to fix stuff in Linux, heck not everybody has the ability to "boot up from a usb stick and have a working keyboard, using only one USB hole".