Ask HN: Should I be discouraged by many competitors?

I had an original idea for a web startup and was thinking of starting out with building a prototype.

That is - until I discovered at least 3 other competitors which are already doing things very similar to my concept.

Should I be discouraged by that? Should I give up on doing something at least 3 other startups are already doing?

Or should I accept the fact that no matter which direction I choose there will always be some sort of competition?