Linux is the same--all those distros use basically the same kernel.
The differences are what the distro developers put into each distro. Those are the "features" that are being turned off or on. ne distro may use Gnome, and another may use KDE. Same OS underneath, but different desktops, with different features. The difference is that the end user *can* install whatever desktop or feature s/he wants, without being dependent on the distributor.
The biggest difference (as I see it) is that most end users do not want the responsibility of freedom. They'd rather be told how to configure their machine and then bend to how the computer works, rather than the other way around.
As always, I agree 100% with you ;)
The ‘freedom’ part is also why I prefer KDE, since it gives the most freedom to do what you want with the desktop environment (and more control over the computer).
(And unlike the old days, KDE is NOT the resource hog it used to be. It actually has lower resource use than either Cinnamon OR Mate recently ;^D)