[aij]

> I've seen plenty of really scalable systems being built by a small core team of people who know what they are doing.

There is huge difference between building a system that could theoretically be scaled up and actually scaling it up efficiently.

At small scales, it's really easy to build on the work of others and take things for granted without even knowing where the scaling limits are. For example, if I suddenly find I need to double my data storage capacity, I can drive to a store and come back with a trunk full of hard drives the same day. I can only do that because someone already build the hard drives, and someone stocked the nearby stores with them. If a hyperscaler needs to double their capacity, they need to plan it well in advance, allocating a substantial fraction of global hard drive manufacturing capacity. They can't just assume someone would have already built the hardware, much less have it in stock near where it's needed.