The SE was launched in 2016, after the 6S. It is on par with many newer Android models, has a great camera, supports AR, and still feels faster and smoother than almost all of them due to iOS and better touch response time.
That doesn't change the fact that the hardware is 3-4 years old. The SE has nothing that's newer than the 6S which launched in fall of 2015. It also has some components that are from the 6 era, so fall 2014. Like I said, it's still a capable phone (I've had the SE since release).