Where do I start. They are over a thousand "Android" operating systems and ROMs I can choose from. I'm right now running a 6.0 Slim Kat LP on my One Plus Two with a intelli powerplug Boefella tweaked kernel. What does that mean? I can design/control how my kernel utilizes the processor and cores, for better SOT(screen on time) or performance. I can decide whether I want all 8 cores to be utilized for running threads, or just one. Open source for the win! I was a apple fan boy too a few years ago. Until I got into a computers degree and had my eyes opened.
The amount of processing power built into and android phone is ireelevant. The OS is typically bogged down most of the time. My iPhone is a dual core processor and the android phone I had in the past had a quad core processor. Needless to say, the android phone ran much much slower than my iPhone 6s Plus. This is because iOS is much more optimized for the phone.