I don't think the debate over Screen Size is over, but I think it's about wrapped up.
The conclusion is: bigger is better.
For years, corporations like Apple and the consumer alike have been blasting Android phones with massive screens, but years later and 'big' phones from yesteryear seem tiny. The iPhone itself hat a touted 'huge' 3.5" screen when it came out. The iPhone maintained its screen size for five years before bumping up to 4". That jump was small. So small, I couldn't tell the difference from a distance. (Admittedly, I have never owned an iPhone.)
Then there were phones like the HTC HD2 and the Motorola Droid X and their 'massive' 4.3" screens. At the time, these phones looked huge. They felt huge, much larger than any phone on the market. They were a different level of luxury beyond having a 'nice' phone. Plenty of trends come and go, like the Evo being the first '4G' phone, but now all the rage is LTE and still no one knows what either of those things mean. Screen size is an idea that's here to stay. The screen is how we interact with the phone the most often.
The Google/Samsung Galaxy Nexus, Samsung Galaxy S3, Galaxy Note, and HTC One X are the phones that really changed everything. They were, by all standards, truly massive. I think the phone to note here is the Galaxy Note itself. It's actually older than every other phone I mentioned, but it's bigger than the iPhone 6 and almost as large as the 6+. The Note looked like the silliest thing in the world. It was too big for a normal pocket, it couldn't be used by one hand, and holding it to the face for a phone call meant a sacrifice in peripheral vision. No one thought it would be successful, it was just too big.
And for most people (if the iPhone 6 and 6+ sales numbers are to be trusted) it sill is. The Note, however, sold millions of units. It wasn't just successful, it was a smash hit. The note broke so many rules and seemed to defy all laws of phone sales, but it garnered a massive audience almost over night. The Note is still around today, and while it's screen size is a bit bigger (5.3" vs 5.7") the phone itself isn't any larger. This is a massive win on Samsung's court, because the Note 4 is actually smaller than the iPhone 6 Plus while having a slightly larger screen (and double the resolution, but that's a different topic, that's probably not as important.)
The 4.7" to 5" range is the new standard, despite the chagrin of many large phone booers. Phones this size are no longer called big, that's a moniker saved for phones like the Note 4 and 6+ (or the Huawei Mate.) Even then, big phones are no longer taboo, nor are the saved for people with larger hands, or large people at all.