Problems tend to have more than one solution. GP's solution should be documented, yes, but the alternate solution that won out was computers being capable of storing a million words or so in plaintext very easily, and doing the same using their compression scheme just isn't really worth the space saved nowadays.
Also, compressing could actually be slower for modern computers. Remember when compressing your hard disk made your PC faster, up until disks became faster, then it actually made it slower?
Today's CPUs are very fast, so the trend could have flipped again, that would be an interesting benchmark.