The whole Amazon Basics thing, cannibalizing sellers, should be illegal. It just victimizes people trying to make a living in a crap job market where online sales are closing street shops.
Sellers are offering a generic product without barriers to entry like trademark, patents. Somebody else notices and contracts the same manufacturer to produce it or finds someone else who will (or makes it themselves). The new entrant sells it for cheaper.
All I see is basic economics. Business cannot stay afloat if their marginal cost exceeds marginal revenue. This is the best outcome for consumers.
The business takes a risk in developing and acquiring a product and Amazon uses the sales data and its platform to pick out winning products and undercut the price. The business is the victim.
The business should protect their product with a patent or other trademark then. Nobody is forcing people to provide Amazon data by selling products on Amazon.
There is no victimhood if the business voluntarily transacts.