I mean the platforms that released between 2011-2013 for the most part did astonishingly worse than their predecessors.
DS - 154 M
3DS - 76 M
Difference - 78 M
PSP - 81 M
Vita - 16 M
Difference - 65 M
Wii - 102 M
Wii U - 14 M
Difference - 88 M
Xbox 360 - 86 M
Xbox One - 51 M
Difference - 35 M
PS3 - 87 M
PS4 - 117 M
Difference + 30 M
So barring the PS4 compared to the PS3 all the dedicated consoles were down massively compared to their predecessors and the PS4's gain were modest in hindsight. Around 236 M units less collectively. Certainly wasn't a healthy period for dedicated gaming devices.
The dedicated handheld market is pretty much dead. The closest thing surviving is the Switch Lite. The Switch was a bounce back of sorts but...
http://www.youtube.com/watch?v=F1gWECYYOSo
Please Watch/Share this video so it gets shown in Hollywood.