This is one of those things that makes me feel the slightest bit more agitated and cynical towards people and society. We all know it's manipulative, and that should be enough reason not to do it. So why does everyone who runs a business do it? Like yeah it does work, but is it really worth subtly eroding your own customer's trust in you? There's an invisible cost of goodwill here.
I remember that for a time, JC Penney focused on honest pricing and abandoned common predatory prices. They came close to bankruptcy and went back to their old ways. The psychology of feeling like we got a good deal is so ingrained into most people that it becomes difficult to run a business without those things