I don't think they'd have to serious-ify She-Hulk to make her Marvel's leading lady. The most popular male MCU characters are goofy as hell, there's no reason why She-Hulk can't be as well.

They didn't need to take away carol's serious flaws that balance the character and make her compelling either with characters like wolverine or her underdog status, self reflection with thinking she's a terrible person either existing yet... they did. I don't trust marvel to push a character well without fucking it up.

Finally, it's noteworthy that She-Hulk has the longest-spanning solo series out of any mainstream female character at Marvel

I have acknowledged that achievement in addition to how the rest of the character's books have done.