It requires some specific models and techniques that wouldn't look good in 3D, though, it's not just cell shading.
But it lets them have a wild variety of player skins and enemy animations without having to redraw everything by hand.
And hand-drawn images look better if the artist is skilled.
https://kofaniv.snk-corp.co.jp/english/info/15th_anniv/2d_do...
In the past this was called roto scoping and used to capture outlines and movement of real objects for animation. The end result is still a hand drawn and shaded object instead of just a screenshot of a posed 3D model.
It's never a sprite though. Even back on the Super Nintendo game sprites had 9 angles * lots of actions * lots of frames for every animation. Multiply that by different lighting in modern games, and using the power of a 3D engine starts looking like an obvious choice. I know lots of games do this for environments. I assumed they did it for everything.
Every motion in every direction has to be animated. It's akin to creating animation by drawing every change on a separate sheet of paper, photographing it, and then stitching together.
The barrier of entry is indeed low. It doesn't take much to start sketching some pixel images. Making a coherent animated whole out if it? Very labor intensive and hard.
(I am instead sure they revealed that the characters in video animation were re-touched recordings of created puppets.)
Many techniques may be part of the creative process and of the production.
Guilty Gears for example started out with 2D sprites and then went 3D with Guilty Gears Xrd[1][2], but with a lot of trickery to keep it looking 2D'ish, though that always was more anime-style than pixel art.
Basically, if you look at where CG is used in contemporary anime, that's where the line is drawn. Many shows will CG their vehicle shots and parts of their action scenes since they call for a lot of perspective drawing with swooping camera movements. They may use and trace over CG dolls to do establishing shots or get static posed characters in a scene, but once detailed acting is called for they tend to revert to drawing in keyframes. Again, generally relying on reference footage to get the acting down, but modifying it to fit the character designs.
I think this is a better video from him showing how it looks in practice: https://www.youtube.com/watch?v=1FrIBkuq0ZI&t=420s