How do people do stuff without debuggers? :D
Another way to develop would be through iterating within a Unit Test that you don't plan to keep around.
Uh, I set a breakpoint and run the app?
To add a bit more context, it's more difficult to configure a debugger when the application is running within something like Docker. How difficult? That depends on the language and tools you're using.
That's an interesting point about depending too heavily on a debugger. I haven't run into anyone too dependent on it, but I could see that happening.
To me, debuggers offer a tighter dev loop when there's something you're stuck on. They also let you 'grok' a call stack in an unfamiliar codebase. "Did this function get called?" "What's in this variable?" etc.