Any one test is useless due to not being able to control for all the random variables that affect how much damage the phone suffers when dropped.
What's useful is looking at all the tests as a group. Suppose 6 organizations do drop-tests. If the phone is badly damaged in only one or two out of the six, or in 5 or 6 of the tests, then you can make some tentative judgments. Still not scientific, but way better than looking only at the results of one drop-test.
Then there's personal experience. If you've never shattered the glass on any previous iPhone, maybe you've been exceptionally lucky but more likely your choices (whether you use a case, how careful you are with the phone, whether you have thick shag carpet on the floor) have played a role and you're not likely to shatter your next phone.
What's useful is looking at all the tests as a group. Suppose 6 organizations do drop-tests. If the phone is badly damaged in only one or two out of the six, or in 5 or 6 of the tests, then you can make some tentative judgments. Still not scientific, but way better than looking only at the results of one drop-test.
Then there's personal experience. If you've never shattered the glass on any previous iPhone, maybe you've been exceptionally lucky but more likely your choices (whether you use a case, how careful you are with the phone, whether you have thick shag carpet on the floor) have played a role and you're not likely to shatter your next phone.