[cheeselip420]

Services and Actions are built on top of pubsub (with separate Request/Response vs Goal/Feedback/Result topics respectively). At least w/ ROS1 - I'm not sure if ROS2 improved things here...

Nodelets are also a disaster, which is why ROS2 kinda fixed this by decoupling nodes and processes.

When you're just starting, ROS can be nice for prototyping - you get a batteries-included platform that can do some SLAM and simple motion planning. But as you start adding new features, you need to figure out how to add those features over multiple nodes. This coordination overhead can quickly bring your system to its knees, or at least make it extremely difficult to debug and troubleshoot when things go wrong.

No one should be building or maintaining middleware. Build robots. Read your sensor data, build a model of the world, decide what to do, then send commands to your control systems. This is the hard part of robotics.

ROS solves the easiest part of robotics (plumbing and process management) in the shittiest possible way.