

Ubuntu Server supports Windows Active Directory. I haven’t used it for anything but authentication (and authentication works flawlessly) and some basic directory/share permissions but theoretically it should support group policy too.
It’d be cool if there was a mainstream FOSS alternative though (there might be, I’ve done literally 0 research), but this works okay-ish in the meantime.
But for management of the actual production servers at work I use a combination of ManageEngine (super great and reasonably priced) and Microsoft’s Entra (doesn’t work well, don’t do it)
I could see that changing. I think a lot of the other competitors went with Windows mostly because they either come from a legacy manufacturer (Lenovo, ASUS) or have been making handhelds longer than Valve (GPD).
But now that SteamOS is practical and able to actually run games i bet well see some shifts. Lenovo is already selling a SteamOS version of their Legion Go S handheld.