The ability to make you successful lies in the process not the idea. Ideas are not unique. Ideas are not businesses. Ideas can’t topple over competitors. The work that goes in behind the idea is what makes you successful.
I never understood why someone would keep an idea secret. Why someone believes the idea is enough to make them successful and no one else can know it. The idea is useless without the work. Tell other people your idea. Make it public. Get their feedback. Battle test the idea to criticism. Know for sure that it is something worth your time, and something you are truly passionate about. Learn to defend the idea, and you’ll be more prepared to build it.
Telling other people about your idea won’t make it less valuable, it will do the opposite.