On the PC we have only three GPU vendors: AMD, NVIDIA and Intel, all three of which have been around for decades and have substantial commercial contracts to deliver stuff that at least isn't horribly broken, as well as the users regularly updating their drivers in case bugs (or, for major AAA titles, hand-optimized shaders) appear.
Meanwhile in embedded space, Broadcom can't even be arsed to implement PCI Express according to spec for a product of the scale and importance of the Raspberry Pi[1], and Android users have literally no say in updating their devices because they don't even have root access on them. Assuming someone discovers a bug in the GPU side, the bug has to go from the discoverer to the device manufacturer, from there to the SoC vendor, hope that the SoC vendor is willing and able to fix the bug, then that has to go back to the manufacturer, who has to prepare a firmware update, test and certify that with phone carriers and their bloatware, and then ship the updated firmware. As you can guess from the process, that rarely happens for anything except the flagship devices from Samsung and Google.
Anything outside of the x86, mainframe and Apple world can plainly be summarized as "it's a horrible horrible mess".
[1] https://www.tomshardware.com/news/raspberry-pi-gpu-success