Hide games in friends list
Solution 1:
The easiest way to achieve this would be to go into your startup folder by typing shell:startup
or shell:common startup
into your run prompt (Win+R). If you find the Steam shortcut in any of those 2 folders, open its properties and edit the shortcut like you would edit your desktop shortcut by appending -nofriendsui
as an argument to the target.
If your folders don't have any Steam shortcuts you could go into your Steam Settings -> Interface and disable "Run Steam when my computer starts". Now just create a new shortcut in your startup folder and edit it accordingly.
Solution 2:
I have not tested this extensively and it may turn itself off occasionally (though it hasn't yet for me), and I don't know if it's synchronized to all devices, but it is in a file that is synched with Steam Cloud so it should be. Obviously a control for the setting is incoming at some point (just like for group events & announcements), but until then...
Close the Steam client.
Open
Steam/userdata/{SteamID3.accountID}/7/remote/sharedconfig.vdf
Press
Ctrl + F
(Cmd + F
on Mac) and search for"bCategorizeInGameFriendsByGame\":true
, and change true to false.Save the file and reopen Steam.
Found while looking through the configuration data as I'm currently working on updating the Steam-Data project, which is an attempt of Reddit/GitHub user ObsidianMinor and myself (and anyone else if you'd like to send a pull request, file an issue, or etc) to document most of the Steam client's local configuration data (trying to leave unknown/unsafe data out of it).
Copy/pasted from the reddit post I made.