Group Policies also allow you to enforce things like browser configuration (proxy, homepage, search engine etc.) wallpapers, screen locks etc.
Can this be done on Linux? Honestly, I have no idea - I think gnome with gsettings/dconf can do that, but can KDE?
That's first and foremost a cultural difference, not a technical. Sure, there's nothing to prevent a Linux vendor to write "install scripts" that copy files willy-nilly across the file system, and many vendors have done this but always with disastrous results and since Linux people hate it, those products are either repackaged or stored in a separate directory far away from other files.
This means installing software at scale (any number of systems), or the question how to cleanly uninstall software it not a question you should ever ask in a Linux environment. The questions you should ask are different in a Linux environment. That is why the tools look different.
Tools like gsettings are culturally alien to the unix world. Instead, home directories are seeded with dotfiles. And dotfiles are kept in version control. Yes, that means that unix people can't answer the quesion how to lock the proxy settings so the user is unable to change them. Instead, should a sensitive system require it, they would instead manage by policy and disallow any traffic outside said proxy.
> This means installing software at scale (any number of systems), or the question how to cleanly uninstall software it not a question you should ever ask in a Linux environment.
And yet this is a problem that so many third-party vendors who try to support multiple Linux distributions have been struggling for years.
> Tools like gsettings are culturally alien to the unix world.
Sure, Linux and UNIX are coming from different roots, but "cultural" means nothing in large organizations, where computers are basically tools not that far from printers, projectors, even hammers. A way to do someone's job. I may hate locked systems, but then I don't have to support users who cannot find their trash bin on the desktop anymore.
You can seed dotfiles for all users, but you can't really enforce that user cannot for example move his taskbar from bottom to the top of the screen without policy enforcement. gsettings/dconf may be culturally alien to this world, but it is (or at least was) solving an actual problem. A problem we may not care about, but some companies do.
Now, I think there is an interesting discussion here to be had - given this latest push from Windows to Linux, as a way of distancing Europe from US, would adding features that bridge this policy enforcement gap between Linux and Windows is desirable?
15-20 years ago I was going to say yes, but back then I cared so much more about Linux as Windows alternative for office use. Today I actually prefer Linux Wild West and how hard it is to lock it into any sort of MDM.
The problem is a self-enforced one by developers. They chase the newest updates instead of focusing on stability. And bundling security and feature changes. And they want to push those updates instead of people pulling it in.
> And yet this is a problem that so many third-party vendors who try to support multiple Linux distributions have been struggling for years?
Are those complaints done in good faith? Most repos allow for custom repositories. And writing a build script are not that difficult. If Calibre, VLC, Firefox, and Blender can be everywhere, so can those applications.
> A problem we may not care about, but some companies do.
Do they? Or is just IT playing with the knobs?
There's a bazillion tools that let you manage files like that across thousands of servers/desktops but the hot one right now in enterprises is Ansible (which would make it trivial to push out an update to such a configuration).
Chrome has a similar file: /etc/opt/chrome/policies/managed/lockdown.json
"Ah yes, but what stops the user from downloading the portable version of a browser and using that?"
You can mount all user directories with +noexec. Also, Apparmor lets you control which applications can make network connections if you want to get really fine-grained.
Other applications have similar policy files. For example, Visual Studio Code has /etc/code/policy.json which—for example—would let your company lock down which extensions are allowed to be used/installed.
Unix has always be about treating users like adults. The administration tools are more about the whole system and the hardware. You can always provide default or sample config, or prevent anything in HOME for being executed, but enforcing wallpapers is silly. But you can still do it by patching the software.