For me, the article makes good points about Lisp in general and makes a good case for lisp vs. non-lisp languages, but other than that it just read like a very good lisp intro.
But this write-up clarifies several things that I've never understood. The package system, for example: http://stevelosh.com/blog/2018/08/a-road-to-common-lisp/#pac...
If I'd seen it ten years ago perhaps I'd have stuck with Common Lisp. Even if it's large and baroque, it has a lot in it.