I think for most people, up until perhaps very recently, their phone usage patterns have continued to scale with the improvements in efficiency and performance

I think for most people, up until perhaps very recently, their phone usage patterns have continued to scale with the improvements in efficiency and performance and progress has been very stagnant. As in, the 2-3 phones they've had over the last 5-6 years all get through the day and then it's charging time if you want to be OK on the next day. Even if you're on 40% at the end of the day, you still have to charge. The two-day mainstream smartphone phone is not here yet.