Seems like better representation could save a few orders of magnitude in data size. Humans only differ at about 1/1000 nucleotides so storing just differences rather than all genomic positions should greatly alleviate the issue. In theory you would just have to store less than a megabyte of nucleotides per personal genome. Probably have to get rid of one-off sequencing errors and quality scores at some point as scaling up to planet wide genomic sequencing.