I'm not sure I understand how having a second OS would hedge against people not wanting to use their first OS, but Fuschia being some sort of backup plan would

I'm not sure I understand how having a second OS would hedge against people not wanting to use their first OS, but Fuschia being some sort of backup plan would at least explain why it didn't really ever get used. My guess was always that it just didn't ever have full support as a replacement due to turf wars with people in charge of Android-related things.