Is your goal in life to land a recording contract? Is your goal to sing on Broadway? Is your goal to sing locally and be paid for your performances? Is your goal to sing in Carnegie Hall?
There is an old joke that goes something like this:
"How do you get to Carnegie Hall?"
The answer: "Practice!"
Being a joke, it still has some truth in it. A great teacher of brass instruments, Dr. Donald S. Reinhardt of Philadelphia, PA, told me that 20% of my improvement was based on what he taught me but the other 80% was my using it. "Using it" means diligent disciplined practice with a great positive attitude AND also understanding it very well and doing EXACTLY and PRECISELY as I was taught.
The lips and the mouthpiece of a brass player are in many ways analagous to the vocal apparatus of a singer, even though there are very distinct anatomical differences. Practicing regularly, consistently, diligently, and correctly can all help prepare a person for success.
Practicing the wrong thing, the ineffective thing, or even the right thing done the wrong way (or in the wrong sequence) can all help contribute to failure or at best, a mediocre result that is simply not good enough to be considered at a professional level. This might sound harsh but it is a harsh reality and there is no replacing knowledge or competency. The instant perfect singer is only a fantasy.
The more a singer knows about the voice and music and the accuracy and legitimacy of that information, the more there will be strong contributing factors to a singer's success and longevity. The world is full of people who haven't taken the time to study music, vocal technique, anatomy, acoustics and other subjects germane to singing. The phrases they use expose their ignorance: "sing from your diaphragm", "place your tone", and a myriad of other fallacious silly insanities which are nothing more than a waste of time, money and attention. It's not just WHO you know. It's also WHAT you know and what you can DO!
Music is a vital part of singing and musicianship is one of the "yardsticks". You can measure a singer's current level of professionalism, or the lack thereof, by their depth and breadth of knowledge and skill of music. Additionally, technique which allows the singer to artistically execute stylistically correct singing is a make-break factor in a singer's career, both short term and long term.
"If you're not growing, you are dying", when it comes to the arts.