[GORDON HUMMEL]

Actually, the comparison is more like apples & oranges. When the Brick came out in 1983 it sold for +$3K; and it was only a phone. Thats over $9K in todays dollars.
The size was based on battery and component requirements.
What computer did you have at home in 1983. The PC was just becoming available, but it was the solution with people trying to find the problem!
Components came from 1-2" wafers with yields +/- 50%. Today 12"/300mm is standard with much better yields. I understand 450mm is just around the corner.
Phones got smaller & at the same time became more powerful, mostly because of Moores Law.
Phone power increased, but then so did the device with the addition of the camera in the phone.
As networks increased in speed, it only seemed logical that internet type functions be available on your handheld device.
It got bigger because of the screen size demands by the users.
Tablets are in the middle, between laptops & phones.
I still have my leisure suit in storage!