LZ4 is only one of the many variations on the basic principle of the LZ family of algorithms, which is to replace repeated sequences with references to where they were before.
What does amaze me a little, is the fact that the rather more complex Huffman algorithm was published and implemented decades before LZ.
Maybe. It might just be that the tricks it plays matter a lot on newer CPUs, and older fast compressors played older tricks.
I think the ratio of CPU cycles to i/o bandwidth is what really matters. Presumably the optimal tradeoff between CPU throughout and compression ratios depends on that and varies over time.
What does amaze me a little, is the fact that the rather more complex Huffman algorithm was published and implemented decades before LZ.
The core idea of LZ, however, has been known for centuries: https://en.wikipedia.org/wiki/Iteration_mark