Why would you leave? It's your job has a band mate to support others and help get the best performance out of them. Even in the studio, encouraging creativity could produce a part which was better than the original. Mixing is also essential to get right; you can't just say, "Make sure the bass is audible.". It's about the whole mix and making sure everything is audible but tight and punchy. A band is only has strong has its weakest link.