Why, please, enlighten me, sir.
I don't know if I can but I'll try. As I said you can't squeese 4 bits of data into 1 bit. Some data is very compressible and some is not. Graphics are very compressable. If a child draws a smiley face on a piece of paper and you scan it and generate a 1 MB file, you will have a very compressible file, maybe 100 to 1. If you have a tightly written piece of assembly language code for an embedded system, you will not be able to compress it very much at all. Quite possibly not at all.
So when you start considering all the different structures in a single cell, then all the different kinds of cells in the body and all the different systems in the body you start to realize that it can't be done. DNA is often discribed as having lots of wasted space, even human DNA. It's job seems to have more to do with how to build proteins than with how to design a body. Consider the almost infinite possible number of configurations of the trillions of cells that make up a body and you can quickly realize 750MB is not enough.