> Scaling vertically only buys you time until you are forced to scale horizontally.

Why not both?

> That and "one huge server" is rarely the best design decision.

I never claimed to build only one server. Only that dedicated scales vertically far more than cloud.

There's absolutely nothing stopping me from buying multiple 4TB servers if I wanted to. The reason you go vertical is because Intel's QPI is ~25.6 GB/s (That's big-bytes: so over 200Gbit), far faster than any switch or router on the market. (10-gbit Ethernet, or maybe fiber at 40-gbit if you go really expensive)

You CANNOT scale processes faster than Intel's QPI. Vertical scaling gives you faster communications than even the most expensive switches on the market.