I strongly agree on the refactor, but for debugging I have another perspective: I think debugging is changing for the better, so it looks different.

Sure, you don't know the code by heart, but people debugging code translated to assembly already do that.

The big difference is being able to unleash scripts that invalidate enormous amount of hypothesis very fast and that can analyze the data.

Used to do that by hand it took hours, so it would be a last resort approach. Now that's very cheap, so validating many hypothesis is way cheaper!

I feel like my "debugging ability" in terms of value delivered has gone way up. For skill, it's changing. I cannot tell, but the value i am delivering for debugging sessions has gone way up