As long as price per capacity / storage density increases exponentially, isn't the best solution to transfer your storage to a newer medium over and over rather than taking a bet on a long term durability of a medium that we have no way to test (and a bet on the durability and forward compatibility of the device to read it).

A single $500 20TB hard drive can contain 30,000 CD ROMS and 500 Blurays. Surely the economics are there.