He uses the hash table as an example, and I think it's apt. Lisp does feel "old" to me with respect to having 10 different choices for hash tables in 10 different dialects. (I briefly worked with Julia's femtolisp a couple years ago and felt this.)
I also felt it when trying OCaml like 5 years ago. I loved the language, but having to "choose" which hash table to use felt odd.
Newer languages like Go and Rust (I think) both have Python/Perl-like hash tables built-in, or at least close to the core where all libraries can interchangeably use them. I think this is here to stay. Hash tables won :)