My 2022 LT sounded like crap, my 2025 Custom sounds much better; not sure why the difference. The 2022 was a chip shortage truck, maybe they were short on half decent speakers too.
Others have noted that replacing the factory speakers makes quite a big difference, if you feel like spendong the money that's probably your best option. There's a few posts on here about speakers and stereo sound.
As for the volume changing, do these trucks still have that speed sensitive volume control? I've had a few vehicles with that over the years and have never found a reason to use it. Could it be that?