Sometimes talent. Sometimes personality. Sometimes both. Sometimes neither.
There are those with a bundle of no talent and no personality that have become great successes depending on how success is actually measured.
There are so many factors involved. Health is a big deal. Finances are a big deal. Connections are a huge deal. So you need a variety of elements to achieve any goal.
Talent like Vincent van Gogh whose fame will continue for centuries. Would be fun to be a bit eccentric like that but i'd like to live longer though he died too early at age 37.