I don’t believe many people encode or especially decode video with CPU-running codes.
Modern GPUs include hardware accelerators for popular video codecs, these are typically way more power efficient than even AVX-512 software implementations.
> I don’t believe many people encode or especially decode video with CPU-running codes.
Believe what you want but as soon as realtime is not a concern and quality matters you'll be using CPU-based encoders unless you have special hardware for your use case.
> Modern GPUs include hardware accelerators for popular video codecs
... with shit quality encoders because they are designed for speed first.
Decoding is a different matter but even there older hardware can easily end up not supporting codecs (or profiles of them) that you come accross.