As for why a non-powered bike couldn’t just be left around, here are a few thoughts:

- As some people have mentioned, bikes are just bigger, and take up way more sidewalk space. If Bird and Lime have gotten unpopular, a “Bird for Bikes” would probably make people livid.

- Honestly, the fact that Birds and Limes come with Anti-theft mechanisms and GPS transponders (which run on the same battery as the motor I think) makes them a bit harder to steal (and there aren’t easily removable parts or a viable black market for selling them). Even a non-powered bike would need a charge every once in a while if it relied on power for its transponder.

- I think the “we supply’em, you pay us to ride’em, we pay people to charge’em” business model is just a straight up new thing that happened to be first successfully done by a scooter startup. I imagine it would be hard for a person in a minivan to pick up tons of bikes for charging without having to remove their minivan’s seats. Again, scooters being small is a big advantage, which is probably also why bigger “sit down” vespa-style scooter startups don’t seem to be a factor right now.