Character who only became interesting and useful once someone writing her realized women are human beings: Sue Storm, who has been 200% improved since Lee/Kirby. In fact, she may be one of the very few Marvel characters where the Lee/Kirby version inspires no nostalgia whatsoever. The single most degradingly sexist character from an era already deeply so.
I totally loathe Stan Lee's Sue. I remember that one story that purported to defend her presence in the FF because Abraham Lincoln had a mom, so women have SOME use, apparently. Then there was the Hulk story where she said she wouldn't be much use finding the Hulk, to which Ross snorts that a pretty girl is ALWAYS of use to keep the men's morale up. To which Reed says, "That's just how WE feel about Sue." Yes, being able to whistle at an attractive ass as it walks by in tights certainly could cheer up soldiers, absolutely. Maybe comfort women too! Gick.
Byrne's in the 80s, who goes on and on about how liberated being a housewife makes her feel to a TV interviewer, isn't much better, but at least Byrne let loose the actual extent of what Sue can do. But I think Lee just made her invisible so it'd be easier to forget she was there.