One thing I e learned is that drops depend on your luck. The 5 beat the s3 in one, but the 5s cracked. Even though they're the same in terms of design.
Always fun to watch these videos, but the outcome is extremely random. In this case, the iPhone faced a very brutal flat drop, whereas the S4 landed more on it's side.
Unless you build a rig a drop 10+ phones, you can't say much conclusively. Other than it seems that phones aren't too fragile these days.