During the 1920s the LNER was investigating high speed trains, and the germans had a high speed diesel railcar and the swiss had some very clever electric technology.
Because the infrastructure was there and they were familiar with the manufacturing they rejected both alternatives and built the A4 streamliners. Ten years later Mallard went on to break the steam speed record, and steam traction remained king until the middle 1950s.
Now, in the 21st century, no-one would consider even diesel for high speed operations, and electric is everywhere. Steam is for hobbyists and museums. And yet, Mallard remains magnificent.
The comparison with hard disks? Well, given that the life of a railway locomotive is between 20 and 60 years, we are around 3-4 generations on from the decision not to buy the flying hamburger. What will storage look like in 3-4 generations? How long is a generation? 3 years?
Hard disks are cruising into their Mallard era, but the future won't stop there.
Predicting the future is easy. Getting it right is nearly impossible.