A lot of businesses do this. It's far less risky to copy a successful model than it is to explore the unknown space of products/services and find out what a successful model is, what to price it at, etc.

This is part of the reason systems like the patent system were created for inventions: to encourage people to bother exploring risky unknown spaces to develop inventions by granting them essentially a short term monopoly to harvest their reward which they would then compete against after a time period so society could further benefit from their finding by allowing competition to drive prices down and iterate on those inventions.

Obviously the patent system doesn't really serve this purpose anymore like so many systems that have been sidestepped/bypassed, changed through regulatory capture and corrupted by pure profit seeking behaviors.

It's a little bit different because Amazon claims to be a marketplace at the same time as curating its own specific product offering. It would be kind of like if a mall required all transactions from independent stores in the mall to go thru the malls servers and then the mall started its own product lines to sell based on that data.

Many Amazon sellers only sell on Amazon, or have a large majority of their business sales there. This is equivalent to having insight to almost your entire business.

Most brands at Walmart and other stores are sold many other places.

Yup. Costco’s Kirkland brand is another example.

Except Amazon testified that it didn't do that, to Congress.

https://www.cnbc.com/2019/07/16/amazon-tells-house-it-doesnt...

Yes, other multi-hundred-billion-dollar businesses with regulatory capture do the exact same things. What a comfort.