Getting left behind
When writing applications to rival existing solutions, quite often a lot of work will go into replicating all the existing functionality provided by those same rivals before moving onto the stuff that makes your product unique. This is just wrong.
You don’t need to be perfect in the areas that your competition focus on. You need to be perfect in the areas you focus on and the rest can come later. It’s arse about face, to make everything great before moving onto the things that your business is about. People don’t need an application that replicates their existing solution already, they want an application that solves the problems they currently have. If you solve those problems, people will be willing to put up with the lagging parts of the system that perhaps they don’t even really care about.
You don’t have to worry about being left behind in areas, if you’re ahead in others.