Retail price maintenance protects the manufacturer's margin. If your retailers get into a price war, their margin will get squeezed down to almost nothing. At that point, they'll either drop your product, nudge customers towards an alternative product that they can make a profit on, or demand bigger discounts from the manufacturer. If your retailers can't make a healthy profit from selling your product, they're not particularly inclined to sell it.
Excessively tight retail margins also degrade the customer experience. As a manufacturer, you generally want retailers who can provide good pre- and post-sales support. If a retailer makes almost nothing from selling a product, they aren't particularly inclined to help customers. They'll spend more time upselling accessories or additional warranties than actually advising the customer and will just deflect all problems to the manufacturer.
Excessively tight retail margins also degrade the customer experience. As a manufacturer, you generally want retailers who can provide good pre- and post-sales support. If a retailer makes almost nothing from selling a product, they aren't particularly inclined to help customers. They'll spend more time upselling accessories or additional warranties than actually advising the customer and will just deflect all problems to the manufacturer.
https://en.wikipedia.org/wiki/Resale_price_maintenance