There are lots of Amazon affiliates in this space, mostly because it’s a strong hobby (i.e. passion) niche with tons of products. Which is good, since tons of these big stores are very general in nature, making it possible for big outdoors sites to possibly even pick one or two stores to recommend (this, in turn, might have other advantages, too, like negotiating better rates with those brands).
Wirecutter's affiliate program might make you doubt the legitimacy of Wirecutter's recommendations -- but, in fact, it's quite the opposite. Wirecutter only makes commission when a reader purchases a product from an affiliate retailer and doesn't return the product. Wirecutter, then, has no incentive to promote inferior products -- if they did, they'd make less money and turn away readers.