https://www.youtube.com/watch?v=x79l7UO_qww
Caveat: The bike used is an e-bike with a powered wheel. The pedals have very little load requirements and no long-term or load testing is shown. As one of the most hardcore roadies you'll ever interact with, personally, I believe this would not last more than a week if it could survive a single ride on a traditional bike and someone like myself based on my first impression of the design. Still, the idea is impressive to me. In practice, a robust enough design will likely outweigh a chain drive by an order of magnitude. The reason the chain and cog transmission is standard is because of the balance of weight to durability. Every single gram matters on a bicycle far more than may be apparent at first.
Exactly, which is why I was trying to think of any actual reasons I might want a belt, except style.