I imagine water resistance comes in handy quite often for many people. It has certainly saved me countless times. Not that I need to go swimming or deep sea diving with my phone, but I have dropped phones in water, been stuck in the rain, spilled a glass of water, etc. I ruined many phones before it became common.
While it is certainly nice to have continued support, I think I’d disagree that forcing companies to maintain software on legacy/outdated hardware is something that should be legislated. I think that would greatly stifle innovation in a lot of cases.