Hosting costs probably. Rolling back a patch is a rare scenario and Steam would have to host every version of every game in their store on their servers indefinitely.
Afaik that’s actually something steam does though, tools like Depot Downloader combined with SteamDB to get the metadata for a target version totally work, I’ve used that in the past to downgrade Skyrim before disabling auto updates. You can do it through the steam console as well.
Hosting costs probably. Rolling back a patch is a rare scenario and Steam would have to host every version of every game in their store on their servers indefinitely.
Afaik that’s actually something steam does though, tools like Depot Downloader combined with SteamDB to get the metadata for a target version totally work, I’ve used that in the past to downgrade Skyrim before disabling auto updates. You can do it through the steam console as well.