Yes, this is true. The old but gold 5/5S iPhone design was carefully tailored to fit people's hands and pockets.
And not the other way around. Sadly Apple's current management are unable to realize this.
Oh, how I miss the headphone jack on the first iteration of their SE phone... Speaking of which, I just recently bought myself an iPhone SE 3rd Gen while it was on sale...
I still have it, use it, and love it.
Sits perfectly in my hand, and fits in any pocket.
I even have a fresh battery for installation, so it'll last me for a long time.