<rant-mode=on>
To me they made it worse.
I don’t like 5.5" phones, prefer 5" but they are all too compromised so forced reluctantly into 5.5". They made the 5 even bigger than 3T I have and made the 5T even bigger than the 5 so its all getting worse every step. They then made the screen bigger but not the battery bigger so predicting worsening battery life to drive more pixels.
Geeks may like bigger phones but I do things like ride a bike and walk with a cup of tea in my hand (as known as having a life) and for me I need 1 handed operation.
I already make use of Android Wear so I can keep the phone in a pocket and glance at my wrist to pick up the phone least, and make heavy use of Anker buds (Life when at home, Slim+ when moving) but a phone which needs two hands to operate, well, I might as well use a tablet and then not have as small as 5.5" might as well have 7"-8". 5" is the sweetspot for phones.

(source)
So many phone designers lost the plot, its a phone.
I just this week got for $270 a 8" tablet with stereo front facing speakers, 4GB RAM, 64GB storage, a SD slot (I put 128GB I got for $20) and if I am to bind up two hands then 8" can do that better than 5.5" which needs 2 hands. 1 handed operation needs 5".
<rant-mode=off>