"Micro" refers to the economy, not the technology. A service in the macro economy is provided by another company. Think of a SaaS you use. Microservices takes the same model and moves it under the umbrella of a micro economy (i.e. a single company). Like traditional SaaS, each team is responsible for their own product, with communication between teams limited to sharing of documentation. You don't get to call up a developer when you need help.

It's a (human) scaling technique for large organizations. When you have thousands of developers they can't possibly keep in communication with each other. You have to draw a line between them. So, we draw the line the same way we do at the global scale.

Conway's Law, as usual.