Compressors are super important for character, groove, and general loudness - so that's mostly the reason why there's so much focus on compressors. Also since we are talking about hardware vs software, compressors are generally a hotly debated topic on that front.
I never understood why someone would go out of their way to get a specific compressor until I tried an LA-2A emulation. Once I heard that signature "squash" from the simulated opto-electrical circuit, it clicked.
I highly recommend this video if you're interested in why compression matters so much https://www.youtube.com/watch?v=K0XGXz6SHco