You're conflating AMD's driver support with Boot Camp as a whole. They are two (mostly) separate things. Boot Camp is the framework Apple provides that allows Windows to be installed on its machines. As part of that framework, Apple provides a software package allows the hardware to work as if it were a native Windows PC. This includes the drivers for the chipset, SSD controller, sound card, WiFi, trackpad, keyboard, et al. They all provide the most basic functionality - getting Windows to recognize that the hardware exists so you get audio from the speakers, etc. Most of the these drivers are fine to get the system up and stay operational. The one exception is the GPU. While Apple provides a GPU driver for Boot Camp installations, they are often very old, and thus not well-optimized for recent games. Back when I would install Windows 7 on my 2011 MBP, the AMD driver Apple provided was at least a year out of date. Up until very recently, I could hop on to AMD's website and download the most current Radeon Mobility drivers that supported the hardware, so it was easy to remain current. Now, this is no longer the case as AMD says straight up in the release notes:
- This driver is not intended for use on AMD products running in Apple Boot Camp platforms. Users of these platforms should contact their manufacturer for driver support.
AMD recently released an updated driver for Windows 10 that will work on Boot Camp systems, however it is based on their old 15.xx core, rather than the newer, better performing 16.xx line. Windows 7/8.1 users are still stuck with an old driver from September 2015.
When I talk about 3rd-party driver hacks, I mean something like
this. It requires messing with the .inf files and disabling driver signature enforcement on Windows - both of which will be well beyond the capacity of most users who may want to install Windows on their Macs just to play the new Doom or something.