> It gets even worse when you consider samples from tumours, where biologically relevant mutations are often found in only a subset of cells. To discover these mutations, a coverage of 100x is often recommend

This point brings up another, implicit, scale multiplier that the average person might assume doesn't exist: that a single individual could need multiple sequences stored.

One can't just estimate required total (uncompressed) storage by multiplying population (mod monozygotic multiple births and chimerism) by the size of one instance of raw sequencing data.