That doesn't change anything. So 12000 of them get advantage, 6000 get disadvantage, 8000 get a DC of 15, etc. It's still not dependent on any specific thing. The only thing that ultimately decides how my PC thinks or feels is d20+cha bonus+proficiency/expertise. There might be some specific beats general thing added to the mix, but those are not common.
You’re mixing things up again. No one uses skills for NPCs to influence PCs as you’re stating. I don’t believe anyone has advocated for that in this thread. I believe there was some “well why not” types of posts, but I don’t think anyone has said that this is how D&D plays or should play,
If instead, we’re talking about how PCs can affect NPCs with skill rolls, then I believe the GM actually can and should factor those additional elements into the DC and whether or not to apply advantage or disadvantage. These are the tools provided to the GM for handling these kinds of encounters. So your assessment that the only thing that matters is the roll plus the ability and modifiers is incorrect.
So again… you are either expressing a concern about something that doesn’t happen (NPCs influencing PCs with social skills) or criticizing GMing that doesn’t consider factors beyond the dice roll and modifier OR alternatively, the overall limited design of 5e and how it handles social interactions.
If the players are to have agency, they need to be able to make decisions that matter with their own brains. You cannot eliminate that and have a game. We are not here just watch how rules simulate characters we have no control over. If I want to do that, I can watch a move or read a book.
But part of what makes that agency meaningful is that it is constrained in some way, or has the risk of being lost or restrained. For example, character death is the ultimate removal of agency for the player (with that character, at least). But that risk is often cited as necessary for meaningful play.
I don’t think it needs to be character death specifically, but there needs to be some kind of stakes… some kind of loss state.
That's the logical end point of this. If the player cannot be trusted to play their character "correctly" and there must be mechanics that force their hand, then why would this logically not apply to everything?
But it’s not about the player not being trusted to play the character “correctly”. It’s about there being risks in play related to who the character is.
Again, this isn’t a concept that we should examine by imagining how it would fit into an existing system that doesn’t already include it. Instead, we should look at games where this is already present. When we do that, I think you’ll see that like
@Maxperson ’s concern… it simply doesn’t apply.
I’m not aware of any game or table that includes any kind of social consequence for PCs that slides down a slippery slope inti every thing they do being determined by a roll.