They don’t. Aisle seats sometimes cost extra due to the slight bit of extra room to wiggle around in, but window seats never do (as far as I’m aware) - because it’s not actually an advantage to sit by a window. This is a nothingburger of an article.

"As far as I'm aware", nice save. Maybe read the article before you dismiss it?

Both airlines were accused of unfairly charging extra for some window seats without warning that there wasn't actually a window there.

Aviva Copaken, a plaintiff in the United suit, said she paid as much as $169.99 to choose a window seat, only to find out upon boarding that she only had a view of the cabin wall.

While American Airlines, Alaska Airlines, and Ryanair are among the airlines that warn customers about this in the booking process, United and Delta do not, the suits say.

How nice of you to play for big corpo that habitually rips off customers by always skirting the extent of what the law allows them to get away with. They must be called out - to the fullest extent of the law - whenever they overstep, however little.

I'm sure multiple lawyers and countless plaintiffs decided to go to court over a "nothingburger".