Lyxen
Great Old One
Why are you even playing/using a given system (instead of another, or even no system at all) if the tools it provides don't facilitate the game you're trying to play/run?
Because they provide a reasonable simulation of the world that my character lives in ? Once more, the devs' own words: "To play D&D, and to play it well, you don’t need to read all the rules, memorize every detail of the game, or master the fine art of rolling funny looking dice. None of those things have any bearing on what’s best about the game."
How are you engaging with the world your character is a part of if you don't even fully understand how to engage with anything in the system you're using for engagements?
Because the rules are not the world. The world is the world, just as in the real world where the "laws" of physics are only approximations of what really happens, the rules only provide an approximation, but they are not the world. And that's the problem with optimisers, they only think in term of rules and therefore they only see the part of the world that the rules approximate, and even then through a more or less narrow filter.
If you don't know or understand the limitations of what characters can and can't do, you can't know if said character is even playing their role correctly.
Because playing one's role is only about what the character can technically do ? Case proven, see above. Moreover, as a person, I know that I'm fairly good with a bow, and that is enough for me to roleplay myself when archery is involved. I can't know how good I exactly am, and I don't need that to function in the world.
That's called optimizing for character internal consistency.
Not at all, it's just called roleplaying, which is the actual intent of the game.