I'm using a AMD Ryzen 3 2200G CPU on a PRIME B350-PLUS motherboard, but Windows 7 Ultimate has no compatible graphics driver
Not AMD does not want to support Windows 7. Although the whole line Ryzen works in W7, except for APUs.
We know that cutting support to Windows 7 is the only way for people be forced to use the junk full of keyloggers called W10. Have a nice day.