It's the long term support version of OpenSUSE that is binary compatible with the entreprise version provided by SUSE (SLES). Kind of the same relation between RHEL and CentOS (before the stream controversy).
In laymans terms it's a stable desktop and server linux disribution. But it's in a weird spot right now as OpenSUSE has stated that this will be the last major version following this release format. The next main OpenSUSE distro will be something based on modular imutable images.
Edit: Apparently there will also be a non-immutable version of Leap 16
If you find yourself wanting to game on your distro again, layering nvidia drivers ontop of immutable fedora is do-able. If you want a more hands off approach you can use bazzite (https://bazzite.gg/), which has an nvidia compatible version and is just a kinoite-based OSI image with gaming oriented tweaks and extra apps.
You can even just rebase to it if you're already using kinoite (and rebase back to kinoite if you don't like it), no need to reinstall your system. The download page has a one-command exemple on how to do that.