That's a good point. I guess a lot of these items don't get talked about much in weight savings discussions, because the cost of packing them is grams, not ounces, and you can get greater returns optimizing the "big 4", or clothing and kitchen kit, as you point out.

It's also a great point that phones and power banks weigh a great deal more than the other items I've listed. Electronics in general are heavy, and yet items like smart phones, power banks, sat messenging/rescue devices, hand held GPS, solar chargers, mp3 players, and standalone cameras (eg GoPros) have become a common part of many peoples kit. Increasingly, people want to stay connected, posting their experiences to Facebook or vlogging for their YouTube channel.

I'm kind of the opposite. When I get out there, I want everything to slow down, and I want to just be in the moment. The only electronics I carry are my phone and headlamp. I don't bring spare batteries if I can get away with it. I'd probably turn the phone off completely and leave it buried in my pack, except that it's the only camera I bring. Even so, I find the urge to see if I have service and use it to entertain myself at times is almost overwhelming. I consider it a healthy mental exercise to force myself not to grab the phone and to focus on simpler things.

The sat messenger/PLB type devices are interesting too. I have never had one of these. It's not just the weight that prevents me from carrying one, it's also the expense. Obviously they cost a lot up front, but there's also the ongoing cost of service. All the trips I've done so far have had low risk, and I haven't felt the need to carry a rescue device. But, for trips in which there is higher potential for something to go wrong, I would consider making this investment (in money and weight).