Ahem!
"with the much greater reliability of appliances today few people ever brother turning off the water supply after using the washer, and their is really little reason to do so, but sticking and dripping inlet valves were a much more common problem on 1950s-mid 70s washers and DWs."
With all due respect to your proven expertise, John, turning off the water supply is still an excellent idea. I do it after every laundry session. The reason is hoses. Even with today's premium hoses clad in braided stainless, leaks and bursting can still happen.
When I lived in Georgia, my neighbor across the street went to Vegas for a four-day weekend. On Day Three, I saw water running out of the garage and down the driveway, so I called their kids, who came over with keys.
Washer hose had burst, filling the entire house with about three inches of water. The laundry pair was in the kitchen, one of those "decorator" setups behind louvered bifold doors. Thousands of dollars in damage, including mold remediation - in Georgia, mold happens fast.
I have stainless hoses AND I turn the water off after use. Cheap peace of mind. Water will find the weakest link in any system.