Cryptographic data, such as hash outputs and elliptic curve points, look completely random and thus do not compress at all. These dominate the blockchain data, leaving only a small amount of compressibility in script bytecodes and counters and such.
Much thanks for the answer. I've searched for answers to why portions of the blockchain might not be compressible. Yours is the best I've come across so far.
I don't want to waste your time but if its not too much trouble, I would like to ask if its not the randomization of data which determines whether hash strings can be compressed but rather the size of the character set and the size of its container. The very few examples I've seen of data inside 1 MB blocks seems to suggest it could be compressed. Maybe not at as high a compression ratio as normal text with its high frequency of vowels and somewhat predictable patterns. But a lower and upper case alpha numeric range of characters could be deemed small enough for a useful degree of compression to occur? Unless the elliptic curve points you're referring to are represented as some form of machine code which tends to have too large of a character set for useful compression to occur?
Anyways, like I said I don't want to waste your time explaining things that are probably very basic. I'm sure I'll figure it out eventually.