Also, the battery pack for a cell phone 30 years ago was about the same volume and weight of an entire smartphone, with a capacity of about 500 mAh. They are also far cheaper if you account for inflation.
Batteries have improved incapacity by about a factor of 10 and the cost per watt-hour has reduced by about 99% in the last 30 year. All without a single advancement in the technology, apparently.