HTC 10 was released in early 2016. It was with Qualcomm Snapdragon 820 SoC and 4GB of memory. Now the former flagship has a system update. For the unlocked US version of HTC 10, click enter Settings then find system update, maybe you can receive the Android 8.0 Oreo push, which has a system package with capacity of 1.8 GB. The security patches date will be in December.
The update cycle is too long for many Android phones, and even the flagship phone has to wait months to receive a system push. After Android 8.0, this phenomenon may be alleviated, and its Project Treble function allows the phone to update the system more quickly.