I would be interested in knowing why. Isn’t the sandboxing supposed to make security better?

I also replace Firefox with LibreWolf and Brave! I don’t do much more than that though; I used to replace GNOME Software with Warehouse, but I eventually found it easier to just remove PackageKit and use Software to install my flatpaks (I still use Warehouse for changing flatpak settings).

I’m guessing they want Chimera Linux to be developed by volunteers rather than employees? They would still need at least a little funding for their website and download links though.