We are stupid, so I will use few words and rely on pictures instead from Insomniac Games' GDC 2020 Conference discussing Ratchet & Clank Development process. I won't risk underestimating how high our level of ignorance can reach, so I will hold your hand in directing your attention to the dates listed on the bottom corner of each picture. Link below for the smart one's among us who wish to learn more.
The Insomniac Games lighting team was able to deliver on the promise of motion picture quality visuals and utilize lighting as a powerful artistic element. This talk will cover the setup, challenges, and lessons learned while paving the way for...
www.gdcvault.com
Im gonna have to push back on this alittle.
Its misleading to say that graphics is the last thing that is worked on.
Its true all the bells and whistles are not worked on or alot of the times turned off so you don't bog down your system during level building/gameplay development.
Usually for a game, gameplay and story-line is being developed seperately from the graphics, as you don't want graphics getting in the way of gameplay development.
So gameplay/story-line is usually done with box (lego like) levels.
However the actual graphic fidelity the game/development team is aiming for is determined in the first quarter of development (if we imagined development being 4 NBA Quarters).
This is when you have a vertical slice that is demoed, which is usually the first gameplay or in-engine demo.
But graphics, gameplay/story are being worked on at the same time. you just have different sub-teams working on it, with their own branches.