A website can grow a lot faster than Moore's law would account for.
Moore's law only states that the density of transistors on a chip will double every 2 years. This will fail because of the Zeno's paradox-like effect of limited miniaturization.
At some point, transistors will have to become molecule size, and then atomic, at which point it should be theoretically impossible to get any smaller.
(Sorry for the derailment, and yes, I also go bonkers over centrifugal vs centripetal.)
Finally, DHH may be amazing at writing frameworks, but he is just about the absolute last person I would trust with anything that resembled math.