SteamOS is Valve’s Linux-based operating system. It features a seamless user experience optimized for gaming, while retaining access to the power and flexibility of a PC, and plays tens of thousands of games on Steam. SteamOS officially ships on Steam Deck, and will soon ship with certain Legion Go S models. We’re currently working on adding support for more devices.
Arch releases updates every day (sometimes multiple times per day). Idk about Bazzite’s cadence, but I’m guessing it’s at least weekly, if not daily.