There is value in looking at amortized price, but keep in mind many people (esp. fans) upgrade more frequently than 24mo. For them the cost differential is much sharper and more frequent.
Also add in the fact that unlike on the Apple side, most of the Android customer base can simply wait a few months or even weeks and get a much better price (see: most LG phones based on my research), or the same specs from a different manufacturer.
Upgrading annually is still within reach for most people, especially if they are enthusiasts. It costs around $2 per day if you want a new phone every year.
Your Android comment is spot on. I'm wary though of comparing specs because that can be misleading. A couple of phones ago I had a OnePlus One which looked marvelous on paper and it ended up being a terrible phone.
