"The greatest improvement in the productive powers of labour, and the greater part of the skill, dexterity, and judgment with which it is any where directed, or applied, seem to have been the effects of the division of labour."
I've been working with teams developing new products as varied as computer chips and drugs, medical devices and engines for more than 20 years.
When I started, it was pretty normal for companies to go outside of the company about 10 to 30% of the time to a subcontractor. Most of the time they had a department that handled this one specialty and experts within it who did the work; sometimes they went outside the company for specialists.
In the last few years, the percentage of work that is assigned to an outside company instead of an inside department has been much higher. Often, more than 50% of the work is actually done by specialists outside the company.
Specialization has become even more specialized and departments within a company often can't compete with specialists outside a company. Specialists thrive with other specialists as coworkers and managers. Every molecule is its own universe; every specialty has its own complexity. Organizations that specialize in one thing get more data points and experience that they can translate into more knowledge and better processes. Experience drives evolution and organizations that get more experience have the potential to evolve more rapidly. An organization that is subcontractor to 5 companies has the potential to add more value for less cost than a department within any one of those 5 companies.
As if that is not enough, it is becoming increasingly common that the subcontractor who has been tasked with some subset of the project work to outsource some or all of their task. Your subcontractors have subcontractors.
If you think this is weird, consider this. If you are making a computer, you will outsource the computer mouse. Do you think that the company to whom you outsource the mouse does not turn to outside vendors to provide the ball and / or shell and / or circuitry, etc.? And that those outside vendors don't have their own suppliers?
The same sort of thing is happening in knowledge work that has been happening for an even longer time in manufacturing.
Specialists turn to specialists who turn to specialists who ...
The division of labor that Adam Smith found so transformative is still not done dividing.