Everyone warns you against being too obsessed/paranoid about your competition.
Paul Graham condenses the main point of competitors in this quote:
A crowded market is actually a good sign because it means both that there's demand and that none of the existing solutions are good enough.
—How to Get Startup Ideas
This assumes two principles. Firstly, in Keynesian economics: 'Demand creates its own supply'. If there is no supply (i.e. no competitors supplying a product for a given need) then there must not have been a demand. And second, on the internet: Winner takes all. If there are multiple competitors then there is no winner. The upshot is: multiple competitors are a good sign. If there is a winner, a single competitor who dominates the market, then it's time to pick a fight.
My book "Choose Your First Product" is available now.
It gives you 4 easy steps to find and validate a humble product idea.