They are like drivers who only direct so as not to make a wrong turn or step but their presence is also considered necessary but not a factor and mandatory. as far as I know there are other people who are also successful in implementation of course they have a strong vision and resilience to face failure and they do it independently. It all comes back to us how wise we are.
Mentors in life are always there including in terms of work and others because teachers at school are actually also quite basic mentors because they are able to educate and direct students on the right path. Likewise with people who are quite experienced in their field of work who can also be mentors for others as long as they have time to teach others. The point is that everyone always has their own mentor in life from generation to generation because our own parents can also be considered as mentors who provide guidance for all things.