If multiple distributions are having the same issue, that means it's a combo driver and pipe wire issue. A lot of newer laptops have terrible speakers that are paired with Nahimic in Windows to sound a bit less shitty, then have the gain jerked up to insane levels.
If you're 100% sure this about speakers missing, you need to get a newer kernel running and see if they get detected, and if not, start tracking the devices through dmesg and ls* device utils to find where it's at. You wouldn't be the only one having this issue if it's what you think it is.
Edit: Arch Wiki says they have everything working, and link to an issue with the bass speakers not working: https://wiki.archlinux.org/title/ASUS_ROG_Zephyrus_G16_(2023)_GU603