I'm not sure about the PC port, (heard it needs mods to avoid major issues?) but as far as consoles go Series X is absolutely the best way to play Nier Automata and it's not close.
I'm fortunate enough to have a ps5 and a XSX, and have the game on both systems. I installed both and took screen caps from each directly (it should be noted that they both run at locked 60).
The Series X version has much better image quality than the PS5 version.
PS5: Left
XSX: Right
full direct caps:
PS5:
https://www.flickr.com/photos/191119797@N07/50625466657/
XSX:
https://www.flickr.com/photos/191119797@N07/50625366086/
It's also quite noticeable while playing that the XSX has superior image quality and resolution. It's not close.
Thought someone might find this useful since it's such a beloved game!
(Also note that Nier Automata is currently available on Gamepass!)