Stability, Stability, Stability. iOS 17 and 18, also macOS Sequoia simply aren't stable enough. Memory leak all over the system, and Photo/Music App, coreaudio services, WindowServer constantly do that, all first-party apps or services. AirDrop sucks. New bug every day.
Apple Intelligence will enter China eventually, but the ChatGPT-powered feature obviously will be replaced by other AI approved there or simply Chinese AI, e.g. ChatGLM by THU which is somewhat related to Apple.