it's a collection of tools bound together by a common build system, set of libraries, and a messaging system with a bunch of tools for introspecting and debuggi

it's a collection of tools bound together by a common build system, set of libraries, and a messaging system with a bunch of tools for introspecting and debugging it. It is, in principle, most of the kind of stuff you want for developing a robotic system, it's just each part is not very good, and it strongly encourages a distributed architecture that more or less makes every problem harder, especially ones which are latency sensitive, like most robotics. Unfortunately there's no unified alternative: your alternative is to basically just put together a similar system from third-party libraries. It's a bit of a pain but not fundamentally that difficult, and you can salvage what's useful from ROS with less faff than dealing with it.