My PS3's too new to support CFW so never got to check, but maybe CFW (not HEN) allows removing unwanted additions? Or maybe even downgrade the system version?
Alternatively, maybe dump your games with the PS3 and play on an emulator on PC if you got the option.
More generally for gaming, DRM-free's usually the least enshittified/privacy-friendly imo, as once you downloaded the installer, zip, etc., the game doesn't care where it came from.
The biggest store for DRM-free stuff is GOG, though you'll quickly learn they're great at making PR disasters if you can live with that. And for platforms like GOG, Itch.io and Steam, there are tools for downloading through the terminal that are as isolated as they get.
For Stean specifically though, do mind DRM's a hit or a miss, and some times both. Also, their Linux version of SteamCMD, needs to be installed system-wide, so I'd suggest getting the Windows version and running through a VM and/or Wine, memorizing the syntax for downloading builds from specific systems.
And uf you must use a launcher, Heroic Launcher abd Playnite are pretty good, neither official products so neither following the design choices of the platforms they support.