The purpose of acoustic treatment is to improve the quality of sound in the room. It make the actual recordings sound better and the mixing process too. Acoustics Treatments is very important than the equipment’s you use to record the track on.
Sound waves travel fast. Fast enough so that what you think you’re hearing from your speakers has already been colored by the surrounding space due to reflection from the walls. ( Assume Sound is like a ball. When the ball bounces inside a closed room, it bounces of each and every wall, so does sound) . An untreated room has a frequency response – the way it reflects sound back – that is uneven. In short, that means what your ears are telling your brain isn’t true. It’s like taking a photograph of a tree in a field and adjusting the brightness and contrast, then applying a color filter. The outcome is a landscape you still recognize, but it isn’t a true representation.
Unless you acoustically treat your studio well, the music and the mixes that you make in the studio wont translate very well in the real world, that’s where most people listen to it.