That's what I'm thinking. Or the events with Kuvira making the spirit cannon caused a chain reaction of scientific advancement at the cost of the safety of spirits, so they're fighting back. It could be both the sacred space and the threat of spirit-fueled technology.

And I'm thinking maybe something akin to 60 years later? But the war with the spirits would have been going on for some time, ravaging technological advances, and even setting some areas of the world back.