Our experience about internal combustion engines are the same. We get lower emissions, better mileage, more horsepower in a given form factor, and vehicles get bigger, have more features, and maybe a smaller gas tank and they feel like they have the same capacity as 60 years ago.

Likewise with phones. The phone I described had a 24-hour capacity, just like the one I have now. But the old one could only do phone calls and SMS, and had an amber LED display. Now my phone has more power, capacity, and connectivity than my first home computer...and needs to be charged daily.

People become accustomed to new things, and manufacturers design their products to utilize new capabilities in the way they think is most marketable. My phone could have a 10000 mAh battery, but then people would complain about weight and thickness.