There is no way of minimizing the import of cover art. It's the consumer's introduction to you.
(Should they be called readers? What does Amazon call them? Probably customers.) If you have a cover that is visually intriguing then people will stop scrolling and look.
The blurb is where you get them to read the sample or buy.
The difficulty of finding the right image that represents the sensibility of your novel is so difficult unless you are straight-line genre.
At some point some stock photo site will actively court the needs of ebooks. It hasn't happened yet although it's possible to find many lovely and usable photos and sometimes vector art. If I had to give advice on this, I'd say use something close until you can find something you love. Unless you can afford to hire an artist and I mean an artist who will produce something specifically for your book, not a designer who just buys something at bigstockphoto and plops it on a template. Make them read the book first. It should be a deal breaker if they're uninterested in reading it. You're paying top dollar for a design, it should include understanding what the book says.