Ubuntu 22.04 LTS comes with the latest GNOME 42 desktop environment with the triple buffering patch included, yet it still uses apps from the GNOME 41 stack due to compatibility issues between GTK4 apps included in the upstream release and Ubuntu’s Yaru theme. Apps that weren’t ported to GTK4 are from the GNOME 42 stack, such as the Nautilus (Files) file manager.
This is also the first LTS release with Wayland as its default (except for machines with NVIDIA GPUs, which will stick with X.org), which is a major milestone. On top of that, it comes with the latest releases of all the various packages that make up a Linux system, and will serve as the base for countless popular Ubuntu-based distributions.
Of course, the countless other Ubuntu flavours also made the jump to 22.04.