Post-hoc justification. There's no analysis of whether that level of hardware was necessary to launch, only that they did get that hardware and did launch.

Looking at the GPU utilization graph, it certainly seems like the hardware was saturated for many days/weeks on end.

Was it worth it to spend that amount up front, yak shave while building the system, etc. vs. pay for cloud GPUs? Probably not in terms of dollars, when their time is also valued in dollars.

Was it worth it for this person? It seems, unequivocally, yes.