More exchanges are not that important. Check the volume registered on Binance by some very new coins (hundreds of mill $).
But letting people know what a cool project you have is very important.
You're right about letting people know about the project and the product that is being built. But I will have to disagree with you on the part where you saying adding to make exchanges isn't important. That's wrong. More exchanges will bring about the much needed liquidity. For a project to be successful, It's important to get everything right and not miss anything.