Sounds more like AMD dropped support for Linux. It's shitty, but I'm not sure what you can expect from distributions if AMD stops updating their drivers for newer versions of xserver.
I don't have laptops with older AMD. My current laptop has the ability to switch between CPU and discrete GPU, but it doesn't work well even under windows, so I disabled it in BIOS.
AMD drivers have been hit and miss for a while, which is one of two reasons I tend to prefer NVidia cards. NVidia took time to make sure their whole stack works reasonably well.