While you shrug it off as not much of an achievement, I see it differently.
One of the smallest compact 35mm cameras with fixed lens in the world was the Minox 35, coming in at 100mm x 61mm x31mm (I believe with the lens cover closed, larger when lens cover is open). It’s lens was a 35mm F/2.8, one stop slower than the RX1’s 35mm F/2. It used a button cell battery and had no onboard flash.
The RX1 is 113mm x 65mm x 70mm, with most of that 70mm being just lens. So in inches, a difference of .5″ x .15″ x 1.5″.
Now considering that the RX1 also has a larger sized battery, holds a memory card, has a 3″ display on the back, buttons on the back along with dials on front and top, ports on the side, a built in flash, a one stop faster lens, etc. plus all the extra hardware inside that is needed to process the images you begin to realize it is quite a technological marvel.
If Sony decided to settle for an F/2.8 lens, I’d imagine it would be even smaller in depth.
Started out doing photography at the age of 6 using an uncle's old 1940 kodak brownie box camera. At 15 years of age, I decided to buy my very own 1975 Praktica SLR camera. I now shoot with a Nikon D850. I do unpaid TFP and commercial paid work.