Honest question: why not swiftly ban 3rd party merchants who do anything that is clearly unethical (e.g., changing product listed while keeping reviews from old

Honest question: why not swiftly ban 3rd party merchants who do anything that is clearly unethical (e.g., changing product listed while keeping reviews from old product, or buying reviewers off to change their review). If it’s an issue of whack-a-mole, ask new 3rd party sellers to post a modest bond. The bond earns interest, and gets returned after N months of good behavior, but gets forfeited if there is a clear ethics violation. Bond amount is proportional to number of items listed, and is set as small as possible to make bad behavior unprofitable. Also, Amazon customer service continues to be amazing for me. Refund basically anytime for any reason, instantly and fast.