Witcher 2 was fully voiced and had all other bells and whistles and still it was made with a fraction of a budget that big western developers usually get.
And yes, they are going all out with CP2077, no strings attached. This is going to be AAA+ plus game, like they like to describe it themselves.
I hate to say it, but comparing this game to Witcher, or Using Witcher as a base, isn't really the correct way to go. From what I understand Witcher really wasn't all that much in terms of Open World. Also, it was the story of one person, pre-determined. He was another persons creation, as was his story. There were no considerations made for female characters, characters of different races and backgrounds, characters of differing roles.
This is going to be an entirely new type of game, and if what we are seeing is true, then it will be a true mic of open world and RPG elements... so while comparisons of some aspects of the game can be made to other games, in the end I have a feeling what we are going to end up with is something unique, and not seen before.
So saying Witcher had a voiced protagonist, is overlooking a whole lot of things... Witcher had one possible protagonist, male, caucasion, with a pre-set history, motivations, and attitude. Cyberpunk at the very least will require 2 voices... one male and one female, at an absolute minimium, if they decide to go voiced. And since every fan of the witcher is quick to point out, every mission had multiple directions the game could be taken in... presumably that means multiple dialogues. That eats up a ridiculous amount of resources. Which is likely why the game didn't have horses, even though that was one of the things they really wanted to include. It also meant the world was more limited. Is there proof that it was the voiced protagonist that prevented these things from appearing in te game... no....
But if it comes down to vehicles or voiced protagonist, or voice and larger world, or voice and a more interactive world, or voice and more story missions, or voice over better netrunning... then for me, the voice gets cut first over any of those things...
In the end, Voiced protagonists are a nice trim to the world, but they have pretty much zero impact on game play itself, or the fun I am having with a game. They are nothing but a nice bow on the package, but if they can add more gameplay to the game by omitting voices, then I can live without them easily.