[volkl48]

The tight closure with just about zero clearance and no bezel is a significant part of the difficulty.

Anything in there, even being closed gently and you notice at the first sign of resistance and correct it - has probably cracked the screen.

Charger/cable/pen tip is common, but even a paper clip could be enough. There's no audible crack and you think nothing of it until the next time you take it out of your bag and the display is broken. That said, this sort of thing will typically have a point of impact/multiple cracks, not just one straight line.

Plastic webcam covers will also do this, just less consistently - they hold the display open a bit and concentrate all the force of the closed lid there.