How does cid make power?

The big problem with many of these arguments is trying to compare extremes.

Take a bread n butter SBM hot street build:
4.00” bore x 4.00” stroke(402ci), exactly 10.5cr, rpm heads to flow 275cfm, port matched Victor, 850 carb, 1-3/4” headers, small solid roller cam, and the motor ends up making exactly 450hp.
This is a combo that has plenty of everything to make the power it does, and more....... except a somewhat limited camshaft.

If you built a duplicate short block, maintained the exact 10.5cr, only bore the cylinders to 4.040”, you’d have a 410”(1 more ci per cylinder).
If you took the entire top end/headers/cam out of the 402 and installed them on the 410, the HP/ci would barely change at all, and the motor would make nearly the exact same 1.119hp/ci it did as a 402..... and make another 8-9hp.

In the real world....... that’s how it works out.