- Peddling charges the batteries, so in an emergency you can turn on the battery
This is generally not a thing.
- Generally easier to repair.
Generally no. DIY ebikes from good components are easier to repair but not without spare parts. Good luck with that during an apocalypse. Cheap factory ebikes as well as expensive factory bikes with mid drives aren't repairable. Finding parts is a problem with the former (today, not in an apocalypse), the other can only be repaired by authorised shops due to parts and DRM.
As others mentioned, batteries may not last too long depending on the make and chemistry. A LFP based DIY would likely last the longest. You have to keep a few spares of all parts - controller, motor, computer, and a spare battery.