

Yes, but I also get into a rage about manufacturers being dicks about it. People by and large don’t seem to understand the IP rating scale is in fact two largely-unrelated scales, and companies slapping IP ratings on their products use that in what I feel are underhanded ways.
The values IPx1-IPx6 correspond to varying levels of resistance against directed streams of water. IPx7-IPx9 are degrees of resistance to submersion. The latter does not imply the former, not even a little bit.
It is in theory entirely possible to build a device that could withstanding being put in the bottom of a swimming pool that’s being slowly filled with water, but failed from the higher pressure of a small amount of water falling on it from a certain direction.
But you still see phones listed just as “IP68”, which tells you nothing. The better manufacturers will explicitly write the likes of “IP65/IP68”; showing that it reaches the 5 rating of “water jets 12.5litre/minute” but not the 6 rating of “powerful water jets 100litre/minute”, but also IP67 “immersion <1 metre / <30 minutes” and IP68 “immersion >1 metre / >30 minutes”.
(https://en.wikipedia.org/wiki/IP_code#Second_digit:_Liquid_ingress_protection)
Yes and no.
Taking advantage of the very real waterproofing of the phones I have owned (past and present), I will just wash the damn thing off under the kitchen tap if it gets dirty, which I have with one of my previous phones done with a high-pressure restaurant-sink-style spray nozzle (I was making beer, and boiling the wort kicks a lot of sticky crap into the air).
That phone was fine afterward, and continued to work for several years after.
Also at a more basic level, it is (at least in theory) an assurance that they actually tested the damn thing, and didn’t just slap a largely meaningless (and as already noted, “bigger number better”) rating on the thing, as is largely the style of our times because consumer protection is dead and regulations are meaningless.
This is exactly the kind of should be done properly, or just not at all. Test it and rate it for the people who do care, or STFU, put the unqualified but perfectly reasonable label of “water resistant” on it, and the bulk of people who indeed do not care (or will be confused) will be no worse off than they are now.
Anything else is just annoying.