Debugging complex race conditions isn't necessarily easy using a debugger either, since halting the passage of time has a tendency to make them go away. Why limit your toolbox? Logging statements and debuggers are both useful methodologies for resolving problems, but in the end, it's as the GP says -- your success is going to depend a lot more on your conceptual understanding of the issue and the application than on the debugging technology.

How do you use a debugger when your application is distributed across dozens of machines?

For threaded langs that might be true - but in js there are no race conditions in that sense, so console.logs are usually fine for debugging "out-of-order" stuff as well. This is ofc opinionated and based on preference, so YMMV.