Charles Darwin’s father was a physician and wanted his son to pursue his own profession. But Charles was not successful in medicine. His father sent him to a religious school to become a priest, but there, too he was unsuccessful. After that, Charles entered the field of natural sciences and became a prominent figure in that field.
According to Hadith, if one fails in one job, he should change his job and will likely be successful in that.
One who sees a shortcoming or flaw in himself should not focus on that but should try to discover talents and abilities in himself and develop them.
Imam Ali (AS) says that along with any shortcoming and flaw there is a perfection and with any perfection there is a flaw, some are tall but lack the desire to make efforts, some are unattractive in face but have good deeds, and some speak fluently but their heart is rigid (they are coldhearted).
No one is good and perfect in everything and no one is incapable and incompetent in all areas. So if someone enters a field and ends up being unsuccessful, he should not complain and say why another person was successful in that field. Instead of questioning God's justice, he should try another field that suits his talents and taste.