@Majeedq, I am unsure of the utility of 4K on a 5.5' inch screen.
Iphone does the basics much better than Android. I have worked pre-production Android tablets in 2012. Also, been a proud owner of nexus in 2013 (good product) and the first ever dual core high end android from LG(can't remember the model). End of the day, Iphone does all the basics admirably. Imessage, Youtube, phone number recognition on webpage and documents, subtle design, average battery life, premium finish, spare parts readily available, good resale value, applications run on bare metal IOS instead of performance compromising virtual machine (like Dvalisk of Android), lag free, limited crashes, intuitive interface etc..... I can go on forever. My household has Windows phone(medium and high end), Android phone and Apple phones(and tablets). I can swear by Iphones. If you need reliability in a pinch, go for it.