Audiophile culture <------------------------------> Pro Audio culture
They often don’t speak to each other, don’t have the same priorities, and don’t know what others are doing. Custom products are custom, and thereby relatively costly and a smaller niche. Consumers and audiophiles are more likely to dabble and resell hardware. Pros pay what it takes to get pro equipment because that’s how they earn a living. They may never explore audiophile brands.
Affiliate links? I think there’s just too much on the market to cover everything. There seems to be a new brand every moment. Retail focuses on brands in the retail channels. Check out @antdroid’s and @SenyorC’s posts here or on other sites, as well as Crinacle of course, to see the vast number of IEMs available.