Maybe not many products that end up on your doorstep, but they dominate in supply chain management. It's a very high and expensive barrier for any startup who would want to compete with Amazon.
I'd call it just another vendor lock-in. Frankly I'm sick of the AWS clone army constantly preaching that spinning up an ECx instance is a better answer than learning "hard stuff" or looking at me like I have a dick growing out of my forehead for not using AWS. Generally it seems to make people lazy and dependent. I don't use it, and will not recommend it because I care about my customers' businesses. Every other 'benevolent' service I can think of which scaled up like that has become a malignant tumor I wish I had never had dealings with. I guess I just won't trust Napoleonic companies again, no matter how nice they may seem. Market share discrimination? lol maybe, but still less fascist than how we rate e-commerce risks, no?