“In real-world design, increasing ability is not about teaching people to do new things or training them for improvement. People are generally resistant to teaching and training because it requires effort. This clashes with the natural wiring of human adults: We are fundamentally lazy. As a result, products that require people to learn new things routinely fail. Instead, to increase a user’s ability, designers of persuasive experiences must make the behavior easier to do. In other words, persuasive design relies heavily on the power of simplicity. (…) Simplicity changes behaviors.” 
“Get your product to be stripped down, focused, and so easy to understand that it’s boring. Look, you’re not in this to impress your designery (sic) friends, you’re in this to communicate your product’s value prop in simple and focused terms. The closer you are to that, the more boring your product will sound- that’s a good thing!” 
It’s more difficult to build something simple than to build something complex. The simpler, the better. It is easier said than done.
We've built ‘innovative’ products. It was difficult to understand, hence to use. Useless.
Simple is hard. But creates value.
Simplicity changes behaviors.