When I play FFVII nowadays the pre-rendered backgrounds still look great. I am always amazed by how well they have stood up to modern fully rendered environments. Sprites not so much

The game would probably be completely stunning if they stuck with some remade super high res pre-rendered backgrounds.

Basically, to get a high production project done you're looking at spending about 50,000,000USD and about 3-5 years of your time. These figures are nothing to be scoffed at, and you're in a huge amount of risk if things go wrong. These huge companies do know what they're doing; they do know what talent and skills to hire for their company. They aren't slack, they aren't stupid, etc. etc. They are just weighing up the risks involved and the extremely high expectations the industry and fanbase expect from such a project.
The point of the quote was it would take ridiculously longer than production of a normal game. I'm not saying that the activities I described would be fast, but there is still a ton of crap already done for them. Chopping of all the writing, design and game engine is a significant savings for any project.