haha. I spent so much time looking for an efficient compression algorithm for audio and movies ... until I finally understood there are already compressed X) However it allow me to discover zst, wich is uncredible with text :

 35M test.log
801K test.7z
  32 test.log.7z
  46 test.log.tar.bz2
  45 test.log.tar.gz
 108 test.log.tar.xz
  22 test.log.tar.zst
2,1M test.tar.bz2
8,1M test.tar.gz
724K test.tar.xz
1,1M test.tar.zst
8,1M test.zip