So you mean as in goodly, saintly, kindly ect? No, I don't believe that the stats have anything to do with a good character. So, what do you mean by "how it is commonly used" because the word "good" is commonly used in about a dozen contexts, especially in gaming circles, especially when you get to different paradigms. Like I said, I'm using thinking in terms of meeting the expected baseline.
Since you don't believe I can't prove it (likely because I have done so multiple times) I'll make this quick, especially since it is 1 AM and I am too tired.
First reason I expect it is the baseline: Because of the basic math of the game. The standard array of stats has the highest stat as a 15. Baseline human is +1 in all stats, so their highest stat will be a 16. Proficiency bonus is a +2, meaning that the simplest and easiest character to make (A Human X with their prime stat as their highest) will have a 16 in their main stat.
You're saying that anyone not putting the 15 in their main stat and then picking a race to get a bonus there is playing the game wrong. Me, I'm saying that the designers wouldn't try to force that to happen. They would want someone to play a mountain dwarf wizard with a 15 starting intelligence, so +2(15) is the most likely baseline.
Second reason is the fairly well accepted math that has shown that a +5 at levels 1 thru 3 gives a 65% success rate against average ACs, DCs, ect, which then trails off and is bumped at various levels as we expect to get stat increases and proficiency increases. I've seen this mentioned in multiple places.
65% proves nothing. 60% is still more likely that not.
So what you have is a first reason that assumes people who don't optimize are playing the game wrong and a second reason that is pure assumption based on 5% more, which proves nothing.
Going back to the first reason, why would I expect that a character with a class would put their highest stat in their prime stat? Because the game tells you to. In the quick builds for every class it lists a primary stat which should be your highest.
Sure. That's reasonable.
So, yes, a 16 in your prime stat is the expected baseline.
15 is not 16. A 14 or 15 in the prime stat is reasonable. An assumption that anyone who does not optimize is playing the game wrong is not.
So your explanation for why they felt someway is because they felt someway... In your mind are feelings utterly arbitrary and indicative of nothing? Because I don't understand how saying that their feelings are their feelings in anyway answers the question of why.
You really don't understand how someone who
feels(incorrectly) that they need to have +2 in their prime stat at first level would
feel relief at Tasha's?
Then what did you mean by saying "The baseline assumption should be 0." If you would explain yourself, this whole process could go a lot faster than me repeatedly asking you to answer the same question over and over again.
Can you show the original post? I wouldn't have said that with regard to PC stats, so it's likely you're confusing me with one of the others in the thread that you've been discussing this with. That or the context was wildly different.
Those are literally your words, from this post right here.
Oh, yeah. The context WAS wildly different. That's saying that the baseline racial bonus to the stat should be 0, for the reasons I lay out above. People who don't pick a race with a bonus are not playing the game wrong or gimping themselves.
Please Max, stop accusing me of fabricating things I can literally quote you saying. It is insulting.
You've completely fabricated me saying that the stat bonus should be 0, instead of +2. The above quote is clearly talking about racial bonuses to the stat itself, not the bonus the stat gives.
And can PCs learn the abilities of NPCs? No. Therefore just because it is a leanred ability doesn't mean everyone is capable of learning those abilities. Therefore, my previous answer stands. Some people are incapable of learning things that others can learn to do.
You do understand game balance and the limitations it imposes, right? Some people being incapable due to rules and not lack of ability doesn't mean that it cannot be learned. Regardless of whether or not a PC can learn it, it's still a learned skill and therefore not a racial ability. It's simply a cultural one.
Sorry, but the feat doesn't require I get a teacher. And who says it can be learned at all. A lot of psychic stories involve it being something you are born with and must learn to use. A learned skill that is rooted in how you are born. Again.
Sure. People can learn to do things on their own. It's how skills develop in the first place. Doesn't stop it from being a skill. And stories from novels or other game systems are not relevant to D&D which has made it a skill that can be learned.
Actually I was referring the Dragon Hide feat, that says that the dragonborn who take it gain sharp retractable claws and tougher scales. Tell me, how did they learn to grow tougher scales than they were born with?
Never grew a callus before?
What did they learn to change their non-retractable claws into retractable ones, because that is a biological feature, you literally have to be born with that ability, that's why cats are one of the few species capable of retracting their claws, and most species aren't. It requires special muscles and a space to retract the claws into.
According to what you just said, all dragonborn can retract their claws without the need for a feat, since it's a racial thing you are born with the ability to do. Oh.......wait. No, apparently it's learned in D&D. A dragonborn that is 50 years old and hits 16th level can take the feat and learn to retract his claws after not being able to do so for 50 years of his life.
Right, so how do you learn to be lucky? You are 100% confident that it is a learned skill, how do you learn it?
Roll dice a lot.

All I know is that it's a fact that it can be acquired later when the PC decides to learn a feat.