No Nougat for your Android phone? You might want to blame Qualcomm
https://twitter.com/LlabTooFeR/status/768737216566792192
..we saw a similar situation with TI which is why the Galaxy Nexus had such a short support life.
According to ROM developer and HTC tipster LlabTooFeR, Qualcomm is not releasing updates to the graphic drivers on the Snapdragon 800 and the Snapdragon 801 chipsets. The former powered the HTC One (M8) and the Nexus 5 which is why those two phones won't be updated to Android 7.0.
Some of the other handsets affected by Qualcomm's decision include the Samsung Galaxy S5, Samsung Galaxy Note 3, LG G3, the Sony Xperia Z3 and other models. Most, if not all of these handsets, probably would have had no problems running Android 7.0. But alas, we will never know. And even if Qualcomm had decided to update the drivers, there is no guarantee that there would have been manufacturer support for the update.
https://twitter.com/LlabTooFeR/status/768737216566792192
..we saw a similar situation with TI which is why the Galaxy Nexus had such a short support life.