There’s also such a thing as diseconomies of scale. My inexpert opinion is that you have to work at enabling economies of scale and that it’s very easy to fall into patterns that turn into diseconomies.

They do, it is the only reason very large companies survive: they live on economy of scale and die of corporate ice age (get large, bureaucratic, slow until freezing). Scale and inertia.

For manufacturing, yes. For corporate governance, nah.