“Name me any popular media that centres around a husband/wife or boyfriend/girlfriend dynamic, where the man isn’t a moron…”

I don't know. I don't watch that type of show personally. I honestly couldn't comment. I know that it's a trope, I also know that it's a dated trope and that shows like that aren't made that much these days. It's a 90s/00s media trope.

Aside from distressingly rare well-written examples of healthy relationships such as Babylon 5, the “foolish husband, responsible wife” trope is almost everywhere. It even figures prominently in a majority of advertising that features couples interacting with each other.

Oh no, not advertising! Woe is me!

I will never understand this obsession and crying about how random couples are depicted in 30 second advertisement clips. I live with adblock so I genuinely never see any of this. It's honestly such a laughable thing to cry about.

As for TV, since you've bought up Babylon 5 let me cycle through shows I've seen on the matter where this dichotomy is not true in regards to man-woman relationships: Turk and Carla in Scrubs, Jack and Anne Bonny in Black Sails, Flint and Miranda in Black Sails, John Silver and Madi in Black Sails, John and Aeryn in Farscape, Holden and Naomi in The Expanse, Ed Baldwin and Karen in For All Mankind, James and Cassandra in 12 Monkeys, Rick/Michonne in TWD, The relationship between the leads in Twisted Metal, The relationship between the older couple in Night Sky (unfortunately cancelled). It's even true in the poorly-written Witcher (Geralt and Yennefer). Now are many of these setups strictly "husband and wife"? No. I don't watch shows focused around those themes generally. But these are equal relationship setups where the man is not depicted as an idiot, and the woman not a genius.