A good presentation does improve sales but imho the value is more important. E.g. if it solves a problem and looks like crap, it's a good enough MVP. A business is not sustainable because of its design, UX or fancy code but because of its value to the customer. A good UX/design/fancy new technology increases the conversion, user experience and what not but it's usually not the key criteria if a business fails or not.

We all see the fancy bleeding edge presentations of successful ventures today but we also forgot or never saw the initial MVP that evaluated the idea/customer and served as a foundation for everything later on.