The coolness of Lisp Machines and Interlisp-D, which is where Raket took its inspiration from.
I have had the pleasure if witness a couple Matthew Butterick talks first hand and they are excellent. He is a great speaker and thinker. I have also seen the subject the article lose his cool a couple times. Which is not cool. Esp given his prominent place in the community. At this point and think he should make himself a bystander.
If you don’t mind Smalltalk, the modern Pharo ecosystem is also amazing.
Just like Notebooks are miles away from that experience, and yet they allow millions of programmers to have an experience that wouldn't have otherwise, even with Lisp Machines/Interlisp-D providing a much better one.
What do you think is inspired by some Lisp Machine? REPLs existed before. Editors existed before. IDEs existed before. Lisp IDEs existed before. For example Interlisp had a Lisp IDE in the early 70s, long before it was morphed into something like a Lisp Machine with Interlisp-D.