Almost any reasonable compression program can compress some files generated by a random number generator, as long as the output happens to have enough of the type of redundancy targeted by the compressor.
The problem is that on average you won't be able to achieve compression if the source of the data is random. Finding one specific output of a random number generator that you are able to compress only proves that that particular output was compressible, not that you can achieve compression on average across the whole spectrum of possible files. If you think about it enough, you will realize there are 2^60 equally likely files containing 20 random 3 bit values. You can't fit all of these files into a space containing less than 2^60 possible outcomes because you will run out of unique output files before you run out of (equally probable) input files. This is the pigeonhole principle and you can read more about it here: https://en.wikipedia.org/wiki/Pigeonhole_principle