Absence of evidence is not evidence of absence.
Translated to startup-speak:
A lack of competitors doesn’t mean no one has ever tried to compete in a given area.
Many aspiring entrepreneurs come up with a great idea and look around to see no one chasing the opportunity.
“YES! Its a greenfield! No competition, I can create a monopoly!”
What the young Padawan has failed to realise is that, in a world where there are virtually no original ideas, a lack of competitors probably means that everyone that has started a business in this space has failed.
The reason for failure is generally not lack of intelligence or hard work. Most obvious opportunities come with hidden obstacles. The more obvious the opportunity the more hidden (and difficult) the obstacle.
When you see a greenfield opportunity, freeze. DO NOT START A STARTUP.
First do some research. Forget your fears of someone stealing your idea. Worse than losing out to a copycat is you losing your cash and time chasing a dream that cannot be achieved.
When you consider how unlikely it is for a tech idea to not already have been thought of, absence of evidence generally means evidence of failure.
Lack of competition generally means your idea is much harder to execute than you think it is.