You can invest your time expanding deep knowledge or broad knowledge.
From a market point of view deep knowledge reinforce your position and broad knowledge expands your territory.
From a business point of view, deep knowledge is not scalable but broad knowledge is. (Few people can acquire a deep knowledge, but everybody can acquire broad knowledge)
From a marketing point of view, deep knowledge is about focused coverage (quality is better than quantity), broad knowledge is about broad coverage. (quantity is better than quality)
As an independant developer, I swear only for deep knowledge but as an entrepreneur I swear only for broad knowledge. A business that only require broad knowledge from its customers can scale, and a business that scale is easier to sell.
The broad knowledge needed for a product to spread is always created by deep knowledge.
Making things simple is only possible when you have both, the vision and the knowledge of the current deepest thing... If it is not deep, then it is already broad, and if it is already broad, you are not making life easier for anyone.