It may sound esoteric but this stuff is actually Super Damn Important, for at least two big reasons: 1. Security. Right now it is hard to trust a container ima

It may sound esoteric but this stuff is actually Super Damn Important, for at least two big reasons: 1. Security. Right now it is hard to trust a container image. Determining provenance and/or reproducibility are hampered by the image format and especially hampered by the charming little quirks of tar. 2. Performance. There are lots of optimisations that would be available if we didn't need to stream out an entire layer before we could do anything use with it. The tar family of formats is, as their name suggests, all about creating linear files intended to be saved to a tape. On a tape random access is bonkers. For a container, random access is a frequent operation. On top of that there's the whole hassle of shipping almost-but-not-quite-identical layers over and over and over. There must be petabytes of wasted bandwidth worldwide by now.