Yes, having mentor that can help person with guidance will help to get good at what you do faster, but I believe mentor is not critical for success is one has clear goal and is willing to start over after each failure.
Mentors certainly play a leading role in providing guidelines, but you won't always find a mentor around to guide you. Those who have great goals and objectives in life will be established in life even without a mentor. However, one thing is that if someone goes down the wrong path in life, a mentor can bring them back from that path and motivate them to lead them in the right direction. However, if a parent can guide their child in the right direction, then that child does not need any mentor other than the parents.