Not when your single camera takes much higher quality pictures than Xiaomi’s triple one, your LCD looks better than their OLED, your phone feels more comfortable in the hand than the 6” one and your chipset wipes the floor with anything they could muster. I can see this phone being very popular with the OS-agnostic demographic shopping in the 300-500$ range in Europe at least in addition to the target audience of older iPhone upgraders in the US.
Sure, if you assume emerging and European markets are ignorant of DXOMark scores. There's a reason why Samsung and Xiaomi are experiencing tremendous growth in Europe while Xiaomi is the #1 smartphone brand in India.
Cutting $50 from the current iPhone 8 price won't suddenly make a single-lens, 4.7" smartphone significantly more competitive given the current landscape.