Yes, and the open-source ones are not accelerated, and the closed-source ones don't work.
https://gpuopen.com/amd-isa-documentation/ for AMD.
https://www.intel.com/content/www/us/en/docs/graphics-for-li... for Intel
ffmpeg is one very small but important part of a complex chain.
Or, I guess the other option is that you’re spreading misinformation.