Has no one noticed that he keeps talking about GPU when the issue is, as has been explained, the CPU usage for processing with 7 days to die? It's a bit like comparing the transmission of two different cars when talking about their performance differences, when it is their engines that are the cause of their vastly different performances.
The minimum CPU requirement for running 7 Days is 2.4GHz
Recommended CPU for running 7 Days is 3.0GHz
The PS4 CPU is 1.6GHz
The Xbox One is 1.75GHz
As you can see the CPU usage for processing the game isn't even high enough for meeting the minimum requirement for running the game, let alone the recommended requirement for running the game. The PS4 Pro and Xbox One X are a bit better at just over 2GHz, but even that is still just the minimum for running it.
The console has to process every single block in the world at any given time, keeping track of any damage done to them, the textures, the location, structural integrity, etc. Unlike most games 7 Days gets compared to, the entire environment is completely destructible(with a few exceptions like traders) which also takes up a lot of processing power.
If I have any of this wrong, I'd love for someone who has better knowledge of technical specs to explain it better. These are just what I have been able to find based on past posts on this subject.