How can you tell the difference between the 3G and 3GS except for speed?
Do you know off the top of your head the difference between the MacBook and MacBook Pro at the time? Would you have known then?
Jobs passed the day the iPhone 4S was released and they were selling the 3GS, 4 and 4S. I’m sure he had something to do with the lineup. The 4 and the 4S were indistinguishable from the outside and the 4S and was only faster.
As far as iPads…
iPad - $350, slowest processor, worse screen of the three iPads
iPad Air - $799, higher price, faster processor (M3), more memory, better screen (anti reflective coating), choice of larger screen
iPad Pro - $1199, higher price, better screen with higher refresh rate and slightly higher resolution, better processor (M3 vs M4), better camera, faster USB C, Face ID, better speakers.