Software packages that are different.
No? The same software is the same software, regardless what distro you install it on.
Gamescope running on top of KDE/Plasma in one distro will not be different from Gamescope running on top of KDE/Plasma in another distro.
Distros are just presets. The vast majority have far more similarities than differences.
What makes one distro different from another, is that it might come with gnome instead of KDE, pacman instead of apt, initd instead of systemd, systemd-boot instead of grub.
Or any other litany of alternative packages that do the same things.
But if you use the same software, then there is little difference between one distro and the next. The main difference is going to be that you installed the same code from a different distributor.
That's literally where the name "distro" comes from.