The more features our gadgets have, the more we integrate them into our lives, and consequently, the bigger the risks we expose our electronics to. Not so long ago, everyday dust or just a couple of raindrops were enough to ruin a fancy smartphone, and your own sweat could be a big (and often unavoidable) no-no for your headphones. Fortunately, plenty of devices are weather-sealed nowadays: it means that thanks to additional seals, water splashes and dust are no longer life-threatening circumstances.
That being said, a weather-sealed device cannot withstand immersion, unless it has additional protection such as IP67 or IP68 water-resistance ratings (even then, liquid damage may not be covered by warranties). A few water drops are unlikely to cause harm to your weather-sealed gadget, but standing under torrential rain would be a lousy idea. These days, consumers see dustproof and splashproof protection as a fundamental feature for mobile devices and wearables, and it's definitely better to be on the safe side.