That anemic device uses hardware decoding in order to be able to decode the video data fast enough - it is literally unable to handle newer video encodings fast enough because it would have to do software decoding, which is were the anemic part totally kills it.

Routers on the other hand have been entirely done in software for ages (with at most hardware support for the encryption in things like SSL, which hasn’t changed in decades) and don’t have to reliably process 4k of data within 20 ms (for 50Hz) time frames.

Your example is very much an apples and oranges comparison.