Other times, specially when i'm tired, i would rather just roll and see if my character can solve it. But that goes for pretty much any mental action. Sometimes i want to role play diplomatic negotiations. Sometimes i just wanna roll Diplomacy and see what dice result gets me.
Yeah, I don't
ever enjoy that. If it got to that point I think I'd rather just ask the GM to just narrate the outcome.
That's mostly how we do it in our group. I might be playing int 8 character, but as a player, i might catch something, like that guard might be persuaded to let us trough. Then, in player to player talk, i say it to my friend who plays bard, and then his bard is doing all the persuading and rolling.
Right. Which is the sensible way to do it. Because if the player of the low-Charisma character jumps in and tries to do the sweet-talking, the GM is going to frown and say, "Ok, you roll, then..."
But here's the thing: the low-Charisma character
might succeed anyway. I mean, it's not really that improbable, unless the DC is super high. But let's say the GM sets the DC at 15, and by "low charisma" we mean 6. Even untrained (no applicable skills) that's still a 20% chance of success.
Which illustrates a point I've been trying to make: low scores (and high scores) in D&D are less significant* than we sometimes make them out to be. An observer who couldn't see the character sheets or the dice rolls, but only observed
outcomes of dice rolls (success or failure), who was asked to guess which character had an 8 in a given stat, and which had a 12, might easily guess wrong after observing a session, because a limited number of dice rolls could easily end up favoring the 8.
Thus my skepticism about the premise that
one must roleplay their stats, because if you work backward from the mechanics, a "low" ability score isn't debilitating. It's just...below average. Yes, the PHB does define Intelligence (albeit less by "defining" it and more by enumerating cognitively unrelated activities) but it doesn't define
how those skills correlate to the scores. There's no text that says, "With a seven Dexterity, you have trouble brushing your teeth and walking at the same time." Which means that if a player wants to express their low Intelligence score as completely unapparent to others, or even "I'm terrible at learning new languages and magic...which is why I became a Fighter...and linear algebra always stumped me, but I'm an excellent tactician and I'm great at solving puzzles" nobody can (or should) tell them they are wrong.
Which gets me back to my (and other's) basic premise: roleplay your characters (and your NPCs, if you are the GM) however you want. But stop judging others for how they roleplay theirs, because any attempt to define good/correct from wrong/incorrect is entirely subjective.
*With the caveat that I totally empathize with, and am guilty of, wanting every +1 I can get in combat, even though the difference isn't really apparent unless you carefully track a lot of dice rolls.