Have you ever gotten into my car during daytime hours in late June?
I’ve worn my vintage Submariner (rated to 200m) while diving. But I only went down 35m. I’m sure the Sea Dweller could handle a little more than a pressure washer. 
If I don’t have a use for it, it’s useless to me. The OP asked about features we found useless. My first thought is this thread ought to be in IMHO; my second is that what’s usefull to one person is wasted on another. Just my opinion.
The SKS rifle’s rear sight that can be adjusted up to 1,000 meters.
Really funny, you Russian bastards.
Overly complicated car, um, interior computers. The ones that handle what happens in the passenger compartment, not the engine control systems. See the BMW 7-series iDrive for the best example of that.
The SMLE’s goes to 2,000 yards. The bullets will (just) go that far, but at that range you simply can’t see the target, unless you’re shooting at a vehicle, in which case a .303 bolt action rifle isn’t going to do much.
Arisaka Type 99 rifles had Anti-Aircraft sights on them. And “dust covers” which not only failed to keep mud and dust out of the action, they made so much noise it was impossible to operate the rifle’s bolt without a lot of loud, obvious clanking noises. :smack: