HDDs will always have the constraint that they are dealing with media in 2 dimensions. Tape has the benefit that the magnetic media is thin enough that it can

HDDs will always have the constraint that they are dealing with media in 2 dimensions. Tape has the benefit that the magnetic media is thin enough that it can be rolled up inside the cartridge to take advantage of the 3rd dimension. Unless there is a significant breakthrough, HDDs in 10 years still won't be able to take advantage of the 3rd dimension. Flash has gone from SLC to MLC to TLC to QLC, and from 1 layer to 144+ layers. I think SSDs will pull even further ahead from HDDs over the next decade thanks to improved manufacturing techniques enabling more and more layers of nanometer scale features.