The founder of Dell found ways of delivering Hewlett Packard's most profitable products for much lower prices but forgot to deliver their quality so within a few years had fallen behind again. Ideas need constant renewal. A great idea will never be perfect and will never work perfectly in all markets and all seasons.
Amazon thrived because it implemented the online bookstore idea better than any of its early rivals did, not because it was the only company to have the idea or the first company to have the idea. It continues to grow only because it keeps trying to improve on the details of the idea and the way it puts it into practise.