It's worth remembering that UE5's core features are highly demanding and the Series X is not new and powerful hardware any more.
If we look at other UE5 games on Xbox Series/PS5, resolutions tend to take a big hit, and framerates are generally unstable. For a game like this that's all about immersing the player in Senua's world and mind, they may not have wanted to compromise that with blurry visuals.
There are hard limits to what you can accomplish at 60fps on 3+ year old console hardware, and the game Ninja Theory wanted to make may well have simply been beyond those limits.