Not sure what they expected...there hasn't been a lot of change from the 12 to the 16 series.
Well, other than making sure there is always a "new" phone to buy to keep the stock/company worth something. You don't need a new phone every year. Less than 1% actually "need" a new feature. You are all just lying to yourself and drinking the cool aid.
I usually try to run at least 4 years. By then, a device I handle all the time is starting to show wear and tear.
Yeah, I keep mine as long as I am willing to put up with it. The last phone I had was at around 7-ish years. It's a phone. I don't use it for gaming, for movies, for "social media", etc.. I don't really give a fuck until it starts sucking at being a phone or there are security problems I cant solve even with a custom firmware.