Device testing gets cut because emulators are free and instant. What gets cut with it is an entire category of failure, and it is the category players actually hit.
What only a real device shows
Thermal behaviour. No emulator gets hot. Real phones downclock after sustained load, and the frame rate you measured is not the frame rate players get at minute ten.
Real memory pressure. The OS kills backgrounded apps, reclaims memory mid-session, and does it differently per manufacturer. Emulators have a desktop's memory and none of this behaviour.
GPU driver differences. Shaders that compile everywhere render wrong on specific chipsets. This is not rare — it is the single most common "only on some devices" bug.
Interruptions. A call, an alarm, a notification, a battery warning. Each suspends the app in a slightly different way.
Input reality. Fingers are wide and imprecise, and they cover the screen. A cursor is one pixel and transparent. Hit targets that feel generous with a mouse are not.
Network variability. Signal drops in a lift, switches from wifi to cellular mid-request, and stalls without failing.
A device list worth having
Not every device — the cheapest current Android you can buy, one mid-range Android two years old, one current iPhone, and one of the oldest iPhones you support. Four devices cover the overwhelming majority of what will be reported.
What a finding from that testing should look like is covered in what a usable bug report contains.
This is what we do day to day — game, app and website QA at Factorial Studio.
