While it’s true acceptable recordings can now be made at home, a recording studio offers many advantages that are just not possible anywhere else.
There’s no replacement for experience
Anyone who has tried their hand at recording can tell you there’s a lot more involved than pointing a mic and hitting record. An experienced engineer will know which mic to use, where to point it, what external equipment will sound best with it and saves you tons of time getting it recorded right the first time.
The main reason to use a studio is the expertise of it’s engineer or producer. This person has, hopefully, logged thousands of hours recording in hundreds of styles of music. Their insight can be truly invaluable to take your production to the next level.
Access to top end gear
A professional studio will have access to excellent recording equipment and microphones. Every sound source is different. Often a combination of a certain microphone and pre amp is required to capture the performance in a pleasing way. A well equipped studio will have different pieces of equipment which can tame or enhance any instrument or vocalist. There really isn’t a “one mic fits all” or “we’ll fix it in the mix” solution. You need to to capture the source as cleanly as possible.
The recording environment
The above are very important, but equally important is the recording environment. Sound needs space to propagate and do it’s thing. There is a lot of science in how wave forms behave and interact with each other. In an untreated space this can cause unwanted reflections, frequency augmentation or cancellation and likely issues in the low end. A studio will have acoustically treated rooms designed to deal with this and capture your performance beautifully.