Improvement for what? Make your own documentary for the Emmys? Ofc every camera could be better, the sky is the limit here, but do you honestly think that the vast majority of iPhone users need a 4K 60fps HDR video recorder in their pocket, instead of for example a phone with more battery life, slimmer and lighter body, etc? Apple is using all these (small) camera improvements as main selling point for each new generation and the people are buying it because they are used to. I bet that most users will struggle to distinguish random photos taken with iPhone 11 and iPhone 12 even in side-by-side comparison.