The Raspberry Pi optimises more for lower cost. For not that much more you can get something like the Odroid N2+ which has 6 cores total, 4 Cortex A73 cores @ 2.4 GHz for performance and 2 A55 cores @ 2 GHz for efficiency.

https://www.hardkernel.com/shop/odroid-n2-with-4gbyte-ram-2/