One thing I can tell you is that Amazon’s traffic is a long way down on twelve months ago. Interestingly, Etsy is going in the opposite direction. eBay are faring even worse.
Here are some figures from SimilarWeb. They show the number of visits to each site in the previous six month period at the time I checked:
Amazon UK December 2018, 546.11 million. February 2020, 473.33 million = -13.32%
eBay UK: December 2018, 377.1 million, February 2020, 275.45 million = -27%
Etsy: December 2018 215.15 million, February 2020 266.31 million = +23.78%
Obviously Etsy is craft based, I certainly can’t sell my products there but I think it’s obvious that anyone who sells products that do qualify may need to have a re-think about where they put their sales efforts. Amazon UK and eBay are, for the time being at least, sinking faster than an old Grimsby fishing smack. If Etsy ever decide to open up their platform to non-craft related products, I think eBay and Amazon will have a very serious problem on their hands.