Why are we still using the same designs / ideas approved by Steve Jobs in 2016? Its been 5 years and the new iPhones look almost exactly the same as the old one

Why are we still using the same designs / ideas approved by Steve Jobs in 2016? Its been 5 years and the new iPhones look almost exactly the same as the old ones - aside from some obvious local optimizations like processing speed and screen quality. It would be great to see something different come out of Apple, but right now it seems like the company is scared of coming out with anything truly revolutionary.