The benefit of debuggers is that you can run experiments on your program while it's running. You don't have to stop, add a new print, recompile, re-run, and do whatever steps were required to get to the point of the printf. As you inspect the data, you can further ask more questions of your program without having to start all over again.

These days, I refuse to start a new language if there is no debugger or IDE available for it. I did that in C using an Ubuntu server with only vim and makefiles all through college, and I'm never going back to that.

I tried web assembly the other day. I couldn't get a decent debugger environment running on it, so I abandoned it.