Bazzite (and Immutable Linux as a whole) is fascinating.
I'm not deep enough in their weeds to perfectly explain it in a concise HN comment, but it's all about having a read-only known-good Linux distro at the root and then layering packages on top, taking much inspiration from server-side containers. It's supposed to be both more secure and more reliable/reproducible/customizable than traditional Linux. You just write in a container manifest which packages you want. When an upgrade comes out, it runs the upgrade, then reinstalls your packages on top.
I'm not deep enough in their weeds to perfectly explain it in a concise HN comment, but it's all about having a read-only known-good Linux distro at the root and then layering packages on top, taking much inspiration from server-side containers. It's supposed to be both more secure and more reliable/reproducible/customizable than traditional Linux. You just write in a container manifest which packages you want. When an upgrade comes out, it runs the upgrade, then reinstalls your packages on top.