<p>I'm trying to compress different 3D files, but find it difficult to find the right software to compress the file.</p>

<p>What are the most suitable 3D file compressors to compress 3D files like STL, OBJ and STEP?</p>

<p>I have tried Draco, and mac zip compressor.</p>

If a general-purpose compression tool using a good compression algorithm, such as 7zip or gzip (for linux and command line enthusiasts) is not providing good compression it is not likely that your files
can
be compressed very much.
This applies to a wide variety of binary files beyond just 3D print files. There is always  a fundamental limit on compression (since it works by finding patterns and removing redundancy in files), and well-designed binary file formats generally can't be compressed very far.
You may however have some luck with changing the settings on your CAD tool to output less detailed files (though you this is obviously a tradeoff.)