Google top 10 are amazon/ebay

Let's say you find a product that has seemingly good metrics, but the top 10 results for that product are all product pages listed on Amazon and eBay. Do these get beaten out by well written content pages about said article, or are they going to be forever buried behind these high authority sites?

They're likely going to buried behind the giants, eternally. There are some exceptions though -

subjective, long(er) tail keywords like "best skateboard" or "skateboard reviews" you can usually rank for, but super broad, commercial keywords like "skateboards" or "skateboards for sale" you will have a pretty hard time outranking.

Generally I stay away from keywords where the top 10 is all ecommerce stores if I have an affiliate site, since it shows that google has a preference for those types of sites.