My question on the three narratives is always: "OK, how is that going to happen?"

"It's a bubble" can answer that question very easily and has plenty of historical precedent. The other two seem to be very vague notions without any obvious intermediate steps that takes us from here to there.

To borrow from the Underpants Gnomes:

Phase 1: Adopt "AI"

Phase 2: ???

Phase 3: Human Extinction/Utopia