Management guru Tom Peters has claimed all you need to do is outsource; and the minimal corporation is a CEO with a computer & phone. This was in the 90s, tho.
Also, the management chain still exists, it's just at a different company. But from the worker's perspective that's irrelevant; just as many people still have bosses.
A hypothetical 'outsource everything' company would be perfectly agile because everything else is fungible replaced with whoever is doing the outsourcing regardless of what is going on everywhere else. The downsides are not only that they are the reverse ofvertically intergrated in that they give up margins to everyone else in the chain and that they have no differentiator other than what they can provide as 'middleware' and outsourcing everything to stay that agile means that it is shrank by design. They would have to provide real value margin as a middleman in order to exist long term vs the clients 'just putting all of the pieces themselves'.
People can talk all day about how people shouldn't have bosses, but they don't stop and consider what civilization would actually look like if that were true. It would look radically different from today.
How much do you pay inhouse councils in your country?