Samsung is forcing Australian Competition and Consumer Commission (ACCC) to prove its waterproofing warranty complaint July 28, 2020 https://mspoweruser.com/samsung-in-hot-water-down-under-for-misleading-ads-about-water-resistance-2/
I've seen the disclaimers before. Water isn't really a problem, but salt or chlorine are. Don't take your phone swimming. I'm sure the same thing applies to any brand. That said if their advertising implies otherwise then shame on them.