Birdy bicycles from Germany used a belt drive system with an internal geared hub at one point and abandoned it in favour of a chain drive due to durability issues.
They were only seeing 500-800kms lifespan on the drive train. That was a few years ago so perhaps the system being discussed has resolved all these issues.
The manufacturer claims 2.5 times the lifespan of a chain. So lets say they are making a 200% lie in hopes of luring Staehpji into buying a belt drive bike, that would mean at least equal durability with chains.
