Not going to happen, they'll just find a way to use more power instead. You probably noticed that for years now, phones and the like have had a fixed battery lifetime of about a day of medium use, even though battery and chip technologies have improved. I'll admit that in terms of efficiency - performance per watt - things have increased, but the goal of the phone manufacturers is not to make things last longer, it's to min/max and find a balance between battery life and power.

With current day technology you can easily make a phone that lasts for a month on a single charge, but it'd be bulky compared to what you can do with it.