Compressors are great! They are an enormous help to engineers and, when used correctly, they make recorded sound…sound better!
But if you over-compress, the results are not good. Over-compression can actually change the timbre of your voice. On the other hand, if you never use a compressor on your auditions or your jobs, you may be missing out on a great tool.
The trick with compressors is to use them correctly. For a primer on compressors and how to use them, check out:
VO Minute episodes 14 and 25.
For more detailed information on compressors, check out:
VO Minute episodes 61, 62, and 64.