Why the N5 still a good phone 2 years later?

First, sorry for my english.

I have the N5, and i'm looking for a new phone... but when I check the specs of the other, the N5 still a good phone with good cpu and good gpu.

But why this phone still a pretty good phone over the years? When compared with new flagship phone, the N5 still in the race.

What is you opinion about that?