I never know how to engage with these kind of discussions, where "literary culture" includes only a narrow subset of the books that are published and read.

The author posts a collage of litfic novel covers and wonders why they're all so similar, but to me the answer seems obvious: litfic is a genre, whether its devotees want to call it that or not, and so it needs a consistent visual language to guide people's eyes in increasingly genre-ified bookstores. He says "every title I see" is like this, but I strongly suspect he'd agree that this is only true because he spots the romantasy section from a mile away and averts his eyes before he has to learn anything about the adventures of Violet Sorrengail.