I would like an alternative to Amazon, but have not yet found anything directly comparable. Despite promises to the contrary, eBay sellers are almost always charging a higher price. Shipping is slow, even from big reputable companies. Amazon has a lock on fast, inexpensive shipping, and it seems to be a very effective moat. If you buy only products 'shipped from and sold by Amazon' then the rate of fraud is low enough that the easy shopping & fast delivery keep you in the fold.
Is Amazon immune to disruption?