I can certainly wear out a bicycle chain in a matter of weeks. If you use a fixed gear bike, your tolerances for chain wear are far looser and you can always a

I can certainly wear out a bicycle chain in a matter of weeks. If you use a fixed gear bike, your tolerances for chain wear are far looser and you can always adjust the spacing to compensate. But for anyone using a modern drivetrain, you will rapidly wear the chain to the point where it will damage the cassette fast enough for it to be economical to replace the chain in order to avoid replacing the expensive cassette (and having poor shifting/skipping cogs). On an e-bike you can wear your chain even faster, especially if you stay on the small gear too much. At the end of the day it's not really an issue though, a chain is 10-15$. That said you're right about the frame lasting far beyond, a good aluminum frame could certainly last over 100'000km