Number of stadiums in Spain have this issue. Might be a design trend from that era.
I think on Camp Nou the entire 1st tier is sunken. Only 2nd tier, vip ring tier, and 3rd tier generate height above the entrance in the stadium.
I think it's related to height. 3 large tiers stadiums not having this design need to have huge height. Not having this and having 105k seats... insane height of the entire structure. Probably pushes the 3rd tier places on the upper section far higher.
The first is not ideal, as mentioned, it has a low visibility that was not fully adressed. I like the overhangs and they give more intimacy and space to enjoy the game without the madness of the whole stadium, if you want that, but the gradiant is killing the show in the last rows.I like the vip rings placement under Laporta's changes. It works because the first section is low and not steep at all as it goes underneath the main 2nd tier which is the biggest. So, even though technically the vip ring is between 2nd and 3rd tier, due to the layout of the first ring... it is still low enough for an amazing panoramic view.
There was no need to demolish the first 2 tiers. They are perfect as they were, just degraded in time.
The roof (biggest one in Europe if I'm not wrong) will manage that on its own.Hopefully they have done everything possible to improve acoustics.