A cover is a more valid signal of a book's quality than ever. If self-pub authors are willing to invest in decent cover art(I know people who have paid over $3,500), it shows they will invest in editing, marketing, and are more likely to have invested more time and effort in the writing. Writers rarely design good covers themselves. Publishers and designers have much more data on what audiences respond to and buy.

It's frustrating when authors have put in the work, invested in editing and used a free subscription to DallE to generate a cover.