Interesting to see how many different interpretations of this there are.
I don't think that the point of questioning "verticality" means, "Should we be able to go
up?"
Of course, we'll "go up". Night City is as much "up" as it is "out".
I think the question is about
freedom of vertical
mobility. Let's take the concept of aerodynes, for example. Say CDPR spends all sorts of time developing engrossing quests, interesting locations, cool characters, etc., all set on the "streets" of NC. Then, they allow the player to fly around in an aerodyne at will. All of that "street-level" work goes completely to waste. It's not sensible for a player to be down there once they have an aerodyne. Why would a bird walk when it can fly? Why would a fish tunnel if it can simply swim? See what happens? The energy of the street-level stuff becomes forced.
Similarly, if the player is freely allowed to use mantis-blades or super-jump abilities to dash up the sides of buildings at will, hop rooftop to rooftop, grapple and fly around, treating Night City like a gigantic jungle-gym, the effect will be two-fold:
1.) The approach to the gameplay becomes relatively shapeless. Players will literally be able to charge around using 6 degrees of freedom, without restriction. Rather than a structured, nicely paced, narratively driven experience...the game will progressively become more and more of a sandbox playground. More of a toy than a game.
2.) One of the primary elements of Night City's allure and mystique -- it's incredible verticality -- becomes quickly common-place and devoid of energy.
Granted, neither of those things is necessarily "bad" in and of themselves, not if that's the
goal. There are plenty of games that rely on it, and use it to great effect: Assassin's Creed, Zelda: BotW, Batman, Shadow of Mordor... I'm just not sure it would gel with the type of experience that CP2077 seems poised to create, though. Definitely a less-is-more situation, I think.