Amazon was pretty famous for never actually posting a profit for their first ~10 years of operation

Amazon would absolutely take a loss on certain products in order to dominate the category, squeeze out competitors and then bring the price back up. It's one of the reasons they're so dominant in general now. Also one of the reasons why Amazon Basics has basically everything that exists and they're usually at or near the top of their respective categories -- third-party sellers simply can't compete.