I'm still digesting much of ... all this info that's coming out of E3 and there's alot in this thread that leaves me apprehensive.
I've said it many times before in other discussions that levels in games as a metric for advancement are getting to show their age. Pen and paper Cyberpunk was ahead of its time in that respect.
Translating a system without numbered level advancement into a computer game like this would certainly have challenges, but, in many ways a system without levels could have interesting role-playing benefits regarding your character's perception of those you encounter in the game. If, for instance, you're a physically weak character, that might emphasize non-physical, stealth, or conversational solutions, where if your character is built physically strong, your character's perception may emphasize everyone else as weak ... and your character might have to learn some lessons the hard way.
With little magic numbers floating over heads, that entire mystique or character perception is trashed.
Oh, they might LOOK strong, but, the number over their head says they're level 2 and I'm level 10, so, no worries.
The same goes for the other disparity where your character encounters numbers well above theirs. It's a level gating, and it's a buzz kill.
It's a design that takes away from looking at the game itself, gets you looking at little magic numbers, and from that you base your sense of confidence for doing the thing, whatever the thing is.
... but, how does all this play into STEALTH, and doing a no-kill play through?
Well, there's THIS nonsense -
... I mean, LEVELS. It's so ludicrous at this point there's people making youtube comedy about it.
How are you going to knock people out, you can't even one-shot kill while they're sleeping? ... or, if for some reason you CAN, then that begs the question why you might not be able to instakill them ... because levels?
It's not really an open world game if you're really only "allowed" to go places and do things within your "LEVEL". Stray from the garden path you're getting your little hand held to follow, and oops, you can fire an anti-tank weapon point blank into the face of someone that's already dead, but if they're too many levels above you, suddenly they'll be upset with you for disturbing them with your annoying tickles.
ugh.
There are certainly ways this can get got fixed. All NPCs could exist in a narrow range of levels around the character where the enemies that are suppose to be tough will always be a couple levels higher, while some enemy types can eventually be surpassed, but, no one is ever 10 levels weaker than your character. They still scale with you, so they can hurt you if you're lazy and don't pay attention, just like any kid can walk up to and cap the toughest hairiest muscled up super thug in the dome, and he'll drop.
This is, of course, a video game, and no one actually expects it to be lifelike realistic. It wouldn't really be much of an escape if there weren't some little bit of overpowered, fantasy fun to it.
All in all, it's a tricky problem to address, and, however CDPR works it out, we'll see eventually come April 2020.
I wish I had elegant answers and solutions to implement a system without any numbered levels as a metric, but, I don't. If when the game comes out and I don't agree with the implementation, I'll do what I usually do, and wait for the modding community to come up with a solution that ... "works" though it might not be elegant, but, less clunky than the systems we've already seen.
Time will tell.