I wonder why all these bikes use the spoke wheels? I don't see the benefit.
are they significantly stronger than cast or forged?
All dirt bikes use spoke wheels. These adventure bikes have off-road aspirations therefore the more off-roady the manufacturers want their bike to be the more likely they will use spoked wheels. Spoked wheels are strong and they are flexible too which is important when hitting a lot of bumps & rocks. Even if they do get damaged they can be repaired.