I'm a professional graphic designer form University of Buenos Aires, Illustrator and specialized in motion graphics for explainer videos. Since 3 years ago co-founded Wideo.co, where I developed as product owner and head of ux/design.
As a founder, I had to make and develop in a lot of tasks and areas. Not only my comfort zone like design, but in new ones like UX/UI and even customer support. And that gave me a lot of tools to know how to listen and take care of users, to develop and improve products.
I've experienced how talking one to one with users can change the way your product evolves and solves problems. What's more, giving answers to complains and taking care of individual issues, brings a great reward: engagement and loyalty. If you're there for your users, they won't go to another "perfect" tool or service, because they don't know if a human being will be taking care of them.
I've had the same questioning once, when I've met my co-founder at Wideo.co He told me something I always remember. If you have a great idea, you were probably have been thinking about it and every detail at least some months ago. So what you can tell in a fraction of time to someone to give a brief idea, won't ever describe the amount of information, specificity, sub ideas, contacts, business model, and every minor detail you've been planing since then. So don't be afraid to share your idea since no one would be able to execute as well as you, if you really have something powerful and value in your mind. What's more, speak about it with every person you met, and get as much feedback as you can (the sooner, the better)
I hope you find my advice useful. Good luck with the project!