I don't think those characterstics are really worth considering when buying switches. For one, you're going to miss out on a ton of options if you restrict yourself to only switches that advertise those features. More importantly, with how mechanical keyboards are constructed, it's highly unlikely the board itself is waterproof. So, what good are waterproof switches when the board itself will fry when you spill your soda on it. I also think dust protection is another thing that isn't going to give any tangible benefit unless maybe you're typing in the open desert or something.

My first keyboard with standard Cherry MX browns last me a decade despite living with a hairy cat. Whenever I removed the caps, there was quite a bit of dust and hair, but it never got bad enough to affect performance and I cleaned it like once every 2 years? In the end, the reason I swapped it out was because the springs were worn out, not dust. Don't know about water though.