Interestingly one of my amazon-niche sites has actually gained from the most recent update. Here's what I think helped:
1. It's no longer about just writing good English (AI too can write good English these days), your writers have to be capable of carrying out in-depth content that actually gives new perspectives. It's not enough to re-write what's already appearing on Amazon or competing sites. Your writers have to think outside the box - which means they need to be supervised by a hawk-eyed editor right from the research-phase of the writing process.
2. Avoid using images that are already being used by other websites. If it is a review article, Google expects you to have your own set of images...apparently to prove that you actually tried out the product prior to reviewing it. Of course, this is not realistic if you're into large-scale affiliate marketing and in that case you're better off getting your images from social media platforms or re-designing images through Adobe.
I can't say I've figured it all out, though. I am also still learning.