Who said that? You can always decrease brightness on a Linux laptop since the first gnome, I myself have gnome3 installed on 2 laptops and the brightness buttons are working perfectly fine.
I could never adjust the brightness of my laptop under Linux. So many people defend Linux to the point of denying people's first hand experience with it.
Didn’t work on my old Toshiba Satellite either. It wasn’t a particularly unpopular piece of hardware or anything.. actually it couldn’t even read the battery % due to an ACPI issue.
The buttons do work. But, some monitors are still too bright at night even with that brightness set to minimum, and hardware monitor controls set to minimum too.
Redshift manages to decrease brightness even further.
To be honest, I've pretty much given up on Gnome. They're removing features I depend on left and right, don't respond to issues, and from everything I've heard, their technology stack seems to be a disaster.
I'm happy just using KDE Plasma, XFCE and i3wm and not having to care about whatever Gnome is doing (except when changes to GTK affects the rest of the ecosystem, like their client side decorations which make Gnome apps look out of place).