Other than the rather rare Charisma saving throws, a character with a 3 Charisma has almost no mechanical penalties if they can "play the DM" well enough to never have to actually roll it in a social situation. Rather than a penalty, they just get the bonus of putting those ability points where they will give a bonus to attack and damage rolls, on which the DM probably doesn't let them talk their way into automatic success.
Well, I do use skills in the game the dice are a part of the game. I even mentioned in a previous post that a Charisma roll is often used as a Reaction indicator to determine initial disposition (if not otherwise known). So it is not like a player can completely cancel the negative of having a 3 Charisma all the time. A 3 Charisma character can expect to have a lot of interactions start hostile or unfriendly.
I just intend that a character with 3 Charisma doesn't force that player at the table to sit out and be quiet during all NPC role-playing interactions.
This can be superior even to having invested character resources to be good at the thing: Rolling, even with a high bonus still has a chance of failure. Talking the DM into your character succeeding without rolling doesn't.
It is not talking your DM into your character succeeding. It is thinking through the situation presented to you. Approaching the situation as if you were your character doing so and presenting a course of action that, in the judgement of the DM, solves the situation.
You make it sound like it is about manipulating the DM and is therefore unearned.
This can be viewed as the epitome of Skilled Play: Knowledge, (whether from experience with the game, good guesswork, or reading the manual/module) and manipulation of the DM grant you the advantage over the adventure challenges. And the points saved by being able to dump scores without suffering the usual downsides for doing so grant you the advantage over the other players.
I don't completely remove ability scores and ability checks from my game. I just listen to player driven approaches first. Intelligence checks and Charisma checks are a part of the game and are not eliminated.
But you do make a good point. Knowledge whether from experience from the game, good guesswork, or even reading the manual/module is a part of Skilled Play.
A player who has played D&D for 20-30 years has every right to put that accumulated experience to bear on being successful at the game.
D&D is a game. Practice and experience makes you better at it.
Reading the manual/module might be cheating, but sometimes it can't be helped. Sometimes you run for someone who is a DM. Sometimes that player who is a DM may know more about the game than you do. They may have ran the module you are running already. They may have ran a campaign that used all the same monsters you used.
But you present this in the context of this someone manipulating or getting one over on the DM by dumping Int and Cha and then using their knowledge to make up for it as a way to 'game the system'. You seem to present this in the worst possible light. I doubt that this really happens all that much.