I would argue that the iPhone 8 should not exist, but neither should the most recent iPhones. Apple seems to be locked in a system of releasing a new phone(s) every year, but they can't actually deliver something that justifies a new model. This isn't a problem exclusive to Apple, it's just very clear with their product line up.

With the solve down in new features and design Apple could have skipped the iPhone 8, XS and XR. Except of cause "the market" and their stockholders expects new phones, regardless of the need.