design Lauren Peters-Collaer 
design Rachel Ake Keuch
Alana Pockros talked to designers and others in the publishing community about trends in book cover design for the AIGA blog Eye on Design:
The guiding principle of “like that book but different” cover design has existed for decades. In the 1960s, the late book designer Paul Bacon pioneered the “Big Book Look,” which we might associate with Philip Roth’s Portnoy’s Complaint or Joan Didion’s The White Album: type-driven covers with large author names and ample negative space that rely more on hue and font than imagery. Philip DiBello and Devin Washburn, founders of the design studio No Ideas, believe we’re currently seeing an evolution of the Big Book Look. “[There’s] a wave of similar covers that play with type intertwined with a key visual in a striking way,” they suggested. In The Look of the Book, Peter Mendelsund and David Alworth’s 2020 monograph, the authors call this mutative style “the interchangeable, big-type, colorful cover.” It’s a look Mendelsund and Alworth first noticed on the 2015 novel, Fates and Furies, and the style they see as the progenitor of the tired “it will work well as a thumbnail on Amazon” rationale.
It is always interesting to hear designers talk about how they view the process and why we get certain trends. But the post itself, entitled “The Endless Life Cycle of Book Cover Trends”, is a variation on the well-worn, trend-focused ‘why do book covers look the same?’ article that has appeared in various guises over the years. Pokros herself references a New York Times article from 1974(!) that explains that jackets must be identifiable on television, and a Vulture piece from 2019 that postulates that book covers are now being designed for Amazon and Instagram. You could also read this post on Eye on Design from 2019 about the ubiquity of stock images, or this The New Yorker piece on design by committee from 2013, or this story in The Atlantic from 2012 (it’s e-readers fault!) among others.
It’s not that they’re necessarily wrong. There are clearly trends and tropes in book cover design as there are in any other kind of design (and pointing them out is fun — I do it frequently!). And there are lots of designs that aren’t great. That’s true of everything. It’s just that on the whole, book covers (like movie posters) don’t all look the same. Not really. Sure, books in the same genre frequently do. Covers sharing similar traits helps readers identify what kind of books they are buying. It doesn’t mean they are B-A-D. Perhaps part of what gets people so twitchy about high-profile literary fiction covers looking familiar is that they don’t like to think of certain kinds of literary fiction as genres?
I don’t know… I’m one of the marketing people whose fault this usually is.
I guess if you really want to get into it, trends in book covers often reflect trends in publishing itself. When similar books intended to appeal to similar readers are published by similar people at similar imprints that are part of similar, very large publishing conglomerates, maybe the issue isn’t really that they have similar covers?
Anyway TL: DR, if you’re seeing a lot of covers that look the same maybe it says more about the kind of books we are exposed to in our daily lives than about the range of covers that are actually out there?