Developers are not investors. They borrow money to build and hope to sell at a profit. It’s just like a new car dealership. The “inventory” isn’t owned by the builder or lot, it’s owned by the bank. The builder pays interest, taxes, insurance, every day a home sits unsold. They are motivated to sell and due to market factors they are starting to offer steep discounts. Now existing homes are a bit of a different story. There is a mix of owners and investors and they are likely locked in at a comparably low rate. If they bought in the last 2 years they may even be underwater. And if looking to move they may need to get a certain price to be able to get into their next home.