ARM invested significantly lately in CPU design, which can be seen through history of job openings and news, so they caught up to Apple. Xiaomi does only SoC integration and CPU configuration (i.e. choosing how much cache, how many units of what, etc whatever ARM gives as options to choose). So, this is not comparison of Apple CPU vs Xiaomi, but Apple vs ARM ;-) CPU design is very long term and risky. NVIDIA has had it (i.e. Carmel soft CPU) and trimmed it significantly (maybe they reignited it again, since they were not allowed to acquire ARM). However Apple has just launched M6. They all know what competition is going to have next few generations through covert/overt industrial espionage (I remember in Intel their competitive analysis team was sourcing info through chain of sources to "wash it")