the problem with that glass is that iit is only designed to handle minor impacts and moderate amounts of static force. (if you look at their lever press test, the 2 circles are so close that they are essentially doing a compression test)
the ball test offers nothing close to the amount of force that the screen will encounter when a phone is dropped from around 4-5 feet.
You know those old devices with LCD screens that never seemed to break no matter how much you dropped them? the glass on those old LCD's are insanely weak compared to the gorilla glass.
The reason why phones today break is because there is no space to buffer any impact. Even strong objects made with metal will flex (look at things being dropped in super slow motion)
With old devices (eg the nearly indestructible phones or old portable game consoles, if they are dropped in super slow motion, the case will almost look like jello but the screen will have no flexing. that is because areas that are not able to to handle the stress of flexing and impact have areas where the screen is reinforced along with reinforced mounting aread around the PCB, then some empty space surrounding those areas with weird plastic structures. The goal is to allow the more tolerant areas of the device to absorb the impact while directing the energy around (and not through) the more sensitive areas.
(kinda like how 5 star crash test rated cars have zones designed to crumple when you crash (that is so your body is not just going from like 30MPH to 0 in 1 or 2 milliseconds , but you may get a few more milliseconds which will mean significantly lower G's on your body. (which is better than just having the entire frame rigid (while it will mean it is easier for the car to be totaled in a crash, your injuries will be less severe).
Electronics did this in the past to stop a 4 foot drop from breaking it, but today many companies decided that key we can save a few mm on each size without redesigning the PCB by simply getting rid of the buffer zones.
Gorilla glass is currently trying to solve a problem that was solved in the past (though they have yet to actually solve it)