I worked on a robotics project with a large team using ROS1. The loose coupling is pernicious: It's easy for everyone to work on their own ROS node in isolation and avoid testing the integrated system. There's no compiler to help you find all the clients of a node, etc.

Loose coupling is good if you mainly use open-source packages and modify one component for your research paper. I'm not sure it's a net positive when building most components yourself.

A big multithreaded program can still use queues instead of locks to share data between threads.