If I had a wish for christmas from GabeN or Valve in general, it would be actually meaningful error messages from steam.
If I had two wishes, I would like a community tool to share configs to make games work that require tweaking.
But I’d be very happy if I got better error messages.
One of the “disk write error” I encountered, is the absence of symbolic link in a file system.
I pluged a used TF card (formatted as exFAT) into my Steam Deck. It works most of the time, but one day I installed a game packed by AppImage, and Steam reported “disk write error”. Turned out exFAT doesn’t support symbolic links, and AppImage uses symbolic links to resolve DLL dependencies.