+1 for QuickSync. Intel 9th gen can transcode HEVC and they don’t have a transcode session limit like Nvidia. An i9-9900K will transcode a half dozen 4K streams without breaking a sweat. I don’t even run a GPU in my plex box anymore.
If you’re running your media server in docker, make sure you pass /dev/dri into the container so it can find the GPU.