The tech actually looks amazing, based on the trailer alone. That IS a young Will Smith, absolutely no question. More convincing than even the Marvel de-aging effect, IMO.
That said... ugh, I hate the flat, digital look of the movie as a whole, and it makes me cringe seeing the hints of how it will play in 120fps. Whatever the opposite of "cinematic" is, this is it. The picture quality looks like a cross between network television and something Michael Mann shot circa 2003, when digital was just starting to become a thing.
I will never ever ever ever ever understand why certain filmmakers insist that all audiences want to be "in" the movie with this hyper-realistic approach. The last thing I want is to feel like I'm "there." When I look at the Mona Lisa, I don't want to be "in" the painting with her. I want to stand back and observe it. I want to appreciate the framing and the brush strokes and what not. If I wanted to be in the painting - or in the movie - I'd buy an Oculus Rift. How about you pull me "in" with STORY instead?