What is "incorrect"? The full sentence that you conveniently chose to cut in the middle before quoting (apparently to fit into some pessimistic forecast about the significance of Linux desktop) reads
> Firefox currently supports hardware video decoding with Intel's vendor specific VA-API only on Linux, which is not supported by NVIDIA.
(emphasis added)
You further wrote:
> Firefox uses Windows Media Foundation, which is cross-vendor, on Windows. It uses MediaCodec on Android which is again cross-vendor.
And? None of those APIs are cross-platform. Vulkan Video will eventually allow developers (including Firefox developers) to write a single code path for video to cover a wide range of platforms and vendors (likely with the exception of walled gardens like Apple-land, although someone might find a way to support like via a wrapper like MoltenVk for Vulkan).
> Firefox currently supports hardware video decoding with Intel's vendor specific VA-API only on Linux, which is not supported by NVIDIA.
(emphasis added)
You further wrote:
> Firefox uses Windows Media Foundation, which is cross-vendor, on Windows. It uses MediaCodec on Android which is again cross-vendor.
And? None of those APIs are cross-platform. Vulkan Video will eventually allow developers (including Firefox developers) to write a single code path for video to cover a wide range of platforms and vendors (likely with the exception of walled gardens like Apple-land, although someone might find a way to support like via a wrapper like MoltenVk for Vulkan).