Day 307/17. Ancient Memories / Future Speculation

More relics from the office clear out.
Anyone remember the Psion? I had a Psion 5, years ago, but I'm not sure this memory card is from a Psion 5. Anyone confirm?
But it is the capacity of just 512KB that is interesting. On the back of the Psion module is written Copyright 1989. 28 years ago and presumably at the leading edge of technology. Pictured with a 256MB CompactFlash card for my first digital camera, plus an early 2GB SD card.
But the real interest is the little thing at the front. That is the MicroSD card from my almost new Mobile Phone with a capacity of 128GB.
The MicroSD is, I would estimate, 1/50th of the size of the 512KB Psion card, yet it has 262,144 times the capacity. That is a 'volume' improvement of a whopping 13,177,200 times.
13 million x the capacity in 28 years !!!!
If it keeps going at this rate, what will our kids be storing on in 28 years? And what content will they be storing that might need 1.5 Exabytes of storage? (that's 1.5 billion Gigabytes).