I’ve used it with a lot of success at my current and previous companies. To address a few of your cons:

• Engineers are quickly comfortable with the tooling and VS Code plugins give you quick feedback. You can also point the plug in at a hosted instance to avoid running a local instance in Docker

• Separation of different types of diagram is often a bonus—too often have I seen architects try to cover too many concepts in a single diagram—instead a Context diagram should define your system and its neighbours, a Container diagram the major pieces of your system, a Component diagram verges on design and is a good place for engineers and architects to converse. If a container or component has a particularly complex workflow, then a supplementary flow diagram helps. If it uses an extraordinary pattern, then a class diagram might help, and so on.

Me too—I was saddened when r/CitiesSkylines didn’t take part in the blackout. A community for a game that became as successful as it is in part due to the hard work of unpaid third-party developers should have been at the forefront of the protests