That is right. AMD's acceleration never got implemented as far as I know. There are some generic methods in the dropdown list, "DirectX VA2" and "Direct3D11 VA", but it is not clear to me that those ever did anything.
For a few years now, hardware acceleration is not really worth the trouble and extra bugs it brings. Or in the case of nvidia, the extra power consumption. At least that is my opinion and the opinion of many others here. As long as you are running sub streams properly, the CPU usage should be quite low without hardware accelerated decoding..