If you are launching a new product you can't compete against entrenched competition in breadth of features. You need to compete against them by finding a small

If you are launching a new product you can't compete against entrenched competition in breadth of features. You need to compete against them by finding a small niche use case or feature and becoming the best piece of software for that niche. Using your tax software example, you would want to become the best tax software ever for pet store owners (random example), then you capture 100% of the pet store market and move out from there.