One of the Samsung Galaxy S8 Active key features is its MIL-STD810G certification. This means that the S8 Active was tested and passed 21 different environment tests, including temperature, dust, shock/vibration and low pressure/high altitude. You can check out Wikipedia and see the long list of test that the device need to pass. From what I've seen, there are more than 21 tests listed and the leaked presentation of the Galaxy S8 Active posted on phonearena.com mentioned, and I quote: "a subset of 21 specific environment conditions..". Maybe passing these specific test is enough to grant yourself a MIL-STD-810G certification.
I've read on another website that the MIL-STD-810G address a range of 29 methods and it's a flexible standard, not a fixed one. This means that phone manufacturers can tailor test methods to match the device they want to be certified. This is why some say that when a manufacturer claims MIL-STD-810G compliance, it doesn't mean that all tests have been done, ever worse, because it's an expensive procedure, maybe no testing was made at all. Companies can conduct their own test and still use the logo and they can come up with their own claims. So when you see a MIL-STD-810G, in some cases this just means that the manufacturer claims that the produce has gone through test that are documented in the MIL-STD-810G document.
That being said, the S8 Active was definitely designed to survive some great deal of abuse. This type of protection will definitely extend the life cycle of the phone. Many people need that type of protection when working in harsh weather conditions that can cause harm to the device.
The LG G6 also carries a MIL-STD810G (MIL-STD = U.S. Military Standard) certification. What I was surprised to see is that the LG G6 looks nothing like a rugged phone, whether the Galaxy S8 Active does. You can clearly see that there is a rather thick frame wrapping the phone, which I assume it was designed to protect the phone from water and dust penetration, as well as impact. The LG G6 also passed 810G military standard tests as the S8 Active for temperature, environmental extreme conditions, pressure, vibration, shock, etc. You can find a more detailed information about the LG G6 810G test on this page.
What we can clearly see here is that phone manufacturers push the protection envelop further and want to provide users with more durable flagship devices. No doubt that showing a 810G certification is the best way to do so. There is no need to do too much, people who heard that and read about this military standard testing once, know what to expect from the phone. Especially those who really must have this type of protection for their phone, or else their phone is going to be damaged.
So who actually needs such a durable and rugged smartphone you ask? There are many situations where this type of phone is necessary, like for people who work in very cold, hot or humid conditions, people who reside in areas with salty fog, people who are at the beach and needs strong sand and dust protection, etc. Of course you don't have to be a professional to enjoy this phone's benefits. Some people just buy Galaxy Active phone because they want more piece of mind, knowing that whatever they do, their Galaxy phone can survive. You don't need to think whether a specific place is good or bad for your smartphone. You can goo with it to the pool, shower or hot tub and not worry about damaging your phone.
If the phone falls on a hard surface, you can rest assured that nothing will happen to it. If it's a rainy day outside and you still want to take photos, you can still do that, again, without worrying about water penetrating the phone and disturbing its operation or damaging it.
Phone part replacement cost a lot. This is why many people buy a protective case to protect their phone. This is of course one thing that you can do. There are companies like Otter Box, UAG, Speck and Zagg, all offer MIL-STD-810G cases.
I personally want to wait for some real-life test that will test the Samsung Galaxy S8 Active and see how it survives some abuse. Having said that, I have no doubt that the Galaxy S8 Active will provide its user with much more extensive protection than the original S8 and S8+.