I read that your watch lasts 4-5 days. That's crazy. My smartwatch gets me a month on average.
I think part of the problem is if battery life improves, device manufacturers will just make the battery smaller. So battery life in things like laptops and smart phones will not improve, but the weight of the device will improve.
Have you seen the Energizer's phones? Things like the Energizer Power Max P18K Pop has an 18,000 mAh battery in it. For comparison, the iPhone 11 pro max has 3969 mAh battery in it. That energizer beast should last for days. Unfortunately, battery life is all it has going for it.
As for laptops, if you pay enough money, you can get a higher end laptop with a decent battery. The Asus ExpertBook B9450 claims to have a 30 hour battery for example, but comes in at $1700 USD. Me, I'm happy with my 3-4 hour battery life and spent $350 CDN on and a bit more for some enhancements (bigger M.2 drive, external USB 3.0 drive, logitech trackball). My laptop has some limitations to it for sure (only 2 USB ports, Mini HDMI output) but has some nice features (12.3" screen with a resolution of 2,736 x 1,824).
David Poole - that Glass battery sounds very interesting. I hope they develop that more soon!
Jeff Moden - The graphene based processors have been talked about almost as much as quantum computers unfortunately and I think it will be many years before they hit the mainstream market, and I'm not even sure it CAN be used to build a CPU can it? If I am not mistaken (which I easily could be... the articles I read on graphene were from 2014-2015 as I couldn't find anything more recent) it is not a very good semiconductor. It is highly conductive. From what I was reading, Titanium Trisolphide would be a better option as it is a good semiconductor like silicon, but can also be shaved down to a single atom thick like graphene.
Now that being said, IBM did make a graphene chip back in 2014, so it is not impossible, but IBM's chip still was missing the band gap and thus is not a good semiconductor. Instead they were focusing on nano tubes at that time which work as a good semiconductor.