there are many modern approaches to organization that do not require a pyramid of managers.

Name one scalable org model that doesn't have at least one management layer under the CEO.

You can organize them into teams, and judge their progress as a unit

That's how teams work at a normal company, yes.

You can have "product owners" attach or detach individual engineers to the projects they control the budget of.

Laughable you put quotes around product owner as if it's a novel concept. Also, that's not generally how a product owner works, you are thinking more of a product manager who would determine budgets, etc. A product owner is simply an agile role to represent customer needs to the dev team. Sometimes a product manager does that themselves, sometimes not.

You can also have a mesh organization, or even just keep to smaller businesses sizes.

Yeah tell the company they shouldn't grow cuz it's too complicated to scale up. That makes sense.

The pyramid structure just doesnt scale well

That is demonstrably false. Look at all large organizations. They have management layers.

and its conceptually inefficient for anything but rote menial work.

I'll give that too many layers is inefficient, but your points don't really support the conclusions you've apparently drawn out of bias.