I don't have to defend why transmogrification isn't realistic, that's why the onus is on you
...No, that's not how anything works. When person X says "I'd like an outfit system", and person Y begins ranting about realism, nobody sane looks to person X to start justifying person Y's street preacher ramblings for them. You introduced the concept of realism as though it were some argument against the idea of customizable character appearance, so I'm afraid "the onus is on you" to defend your own ideas here. I can understand why you'd try to outsource the task, I don't envy anyone trying to defend a collection of ideas this contradictory and nonsensical, but
I certainly can't defend them for you. I can't even take them seriously.
"What is it that makes sense to you about swapping out plate armor for a wizard's robes?", remember? Are you losing track of which posts were yours and which were mine? You type up the gibberish about needing to make sure players half the world away are respecting the sanctity of Vecna and his wardrobe, I correct you, that's the dynamic here. I like a little RP as much as anyone, but you can't seriously expect me to play
both roles.
If you would just be more frank about what is motivating your desire
I don't know, I think I've been pretty frank already, and about something that isn't very hard to understand in the first place. Its my character, more control = good, less control = bad. I even gave you a really simplistic and easy to follow example without too many syllables. I think you're mistaking a shortcoming of comprehension on your part for some kind of obscured motivation on mine, but I don't know what to tell you - I can explain it in plain language until I'm blue in the face, and I certainly have, but I can't understand it for you.
So, you're uninterested in the setting
No, false. I like the setting. You've begun to equate "interest in the setting" and "desperately needs Hide Armor to not look like Leather Armor on somebody else's character in somebody else's game to better fit their idea of said character, or even just their personal preference".
the game is just a cool way to cosplay
No, that's false as well, it not being very good at that is actually what prompted this whole conversation. Are you feeling okay? Is something getting lost in translation? Do you know where you are, what we're talking about?
just don't tell me it's true to the setting, lore, or gameplay
You're in luck - I can't account for your imagination, but I don't think anyone here in realspace did any of that. It has nothing to do with the setting or the lore, just like saving the game, magic maps, freezing time, third person cameras, or any other gameplay abstraction that you've already accepted. It certainly has no impact on the gameplay itself, as has been explained to you so many times already. The separation of appearance and gameplay impact is actually central to the whole idea in fact.