Until you can get a good sound from a good compressor, there’s no use in worrying about getting a great sound from a great compressor because your ears haven’t been trained to tell the difference and to know which parameters do what.
Start with what you have, then answer your own questions.
That’s because a lot of times you don’t have the luxury of trimming everything manually when working with deadlines. In those cases, a Compressor, De-Esser, Gate, Expander, etc are time savers. Some of them are really excellent at what they do. Having said that, I do agree with what you say.
And, because such things are dynamic as a mix evolves…I don’t want to keep going back to the project window and drawing stuff with a mouse when I can make a quick tweak to the compressor threshold and make up and achieve what I need to. Plus half of compression is about the tonal “side effects”.
DeEssing, though…depends on how bad it is…these latest mixes, I’ve just been hitting the Slate tape machine harder…lots of the nasty sibilance goes away. Which is why U87s worked so well to tape, but I digress…DeEssing can be time consuming with a deEsser OR manual…better to back off the mic and set your compressor attack properly.