The insurance pool isnt just bikes. Renters insurance you are insured in the few hundred grand range if you really tallied up what is covered. A couple hundred dollar bike is hardly a dent in comparison to what the premiums are designed to potentially cover.

Bike theft is a fairly big thing here in Amsterdam but insurance is easy to get and affordable. For more expensive bikes they insist on certain types of locks, etc., and it's possible that simply following those requirements is enough to make insured bikes less of a target than uninsured, on average.

We’re starting to see more e-bikes have GPS tracking built into the frame, at least with higher end models. See Canyon, VanMoof before they collapsed, etc

If that becomes more widespread, e-bike theft will be a lot riskier, and hopefully easier for companies to insure.