Still one of the biggest issues in Android.
It's also why despite being over the performance cap for general use it's sometimes hard to recommend last year's phones. Usually they are good for one big update, and then they get filed to the side.
So if a phone launched with Android M, and it's now gotten the Android N update you might be buying a phone at the end of it's update life.
That's the same in iPhone world still, isn't it? Might have gotten better now they released a lower specced phone, but when my 3G got 4.0 and my 4S got 6.0, I may as well have binned them as they were close to unusable