A person can't claim a world record on height by being morbidly obese.
Yeah, but a person could claim a world record on size by being morbidly obese. If they said "I'm the biggest person in the world", they'd be making a statement that can be reasonably judged technically true, even if the listener might mistake their meaning to be that they're the tallest. Anyway, I know what you mean, I just think this is past the line of being arguably "technically true".
Sometimes, we do measure things by a single dimension. Such as height. A person can't claim a world record on hobese.
Area would probably be a more useful measurement for screens but historically, for better or worse, that's not they've been advertised and that's not how consumers are used to comparing them.