Compared to the m1, the a15 processor is definitely much more powerful. Because m1 is a desktop processor, it has a relatively high power tolerance and can accumulate performance, while a15 is a mobile processor, which needs to balance between performance and energy consumption, so the performance of a15 is limited.
a15 is a 5-nanometer process with 6 cores and 15 billion transistors. m1 is also a 5 nanometer process, 8 cores, and more than 20 billion transistors are integrated, so the performance is much stronger than a15