I also wonder what those people have been doing all this time... I also have been mostly working as a developer for about 20 years and I don't think much has changed at all.
I also don't feel less productive or lacking in anything compared to the newer developers I know (including some LLM users) so I don't think I am obsolete either.
At some point I could straight-up call functions from the Visual Studio debugger Watch window instead of editing and recompiling. That was pretty sick.
Yes I know, Lisp could do this the whole time. Feel free to offer me a Lisp job drive-by Lisp person.