gog.galaxy refers to a gaming platform. Everything else is the report is pretty typical. But it would be interesting to see if GOG is the culprit by removing its launch agents and daemons.
The GOG agents are in your user account. The only one that isn't is a launch agent in the main Library folder, but points to an executable in your user account.
EtreCheck does have it white listed as a recognized item, but that doesn't mean it isn't the source of the hijack.
I was surprised you didn't find a Profile entry in the System Preferences. That's usually the case when Safari's preferences are grayed out.
There are other items related to Safari in the user account. Such as this folder:
/Users/user-name/Library/Containers/com.apple.Safari
That folder of items might be where the problem is.
Restart in Safe Mode (restart and hold down the Shift key). Put these items in the trash:
/Library/LaunchAgents/com.gog.galaxy.commservice.plist (this is the root Library folder)
The following are all in your user account:
/Users/user-name/Library/Containers/com.apple.Safari (a folder)
/Users/user-name/Library/Preferences/com.apple.Safari.plist
/Users/user-name/Library/LaunchAgents/com.gog.galaxy.commservice.plist
/Users/user-name/Library/LaunchDaemons/com.gog.galaxy.ClientService.plist
Restart the Mac and let it boot normally. Test Safari.
That, and it's never a good idea to have TeamViewer, or any remote access software always running. Unless you have a real reason for it to exist, remove TeamViewer.