Earlier quoted context omitted.
Typing features affect the way we design APIs. Libraries written in languages with type classes and without them can have completely different designs. If nested pattern matching is not available, this will not affect the APIs, only the function bodies -- because desugaring is local by definition.
That doesn't matter in practice. If two programming languages have the same underlying feature but one has syntactic sugar to make it very easy to use and the other does not (so is quite cumbersome to use) then you'll find that the library ecosystem for the former language will see the feature in widespread use whereas the ecosystem of the latter will tend to shun the feature. This is one of the social factors of pro…
There are already two misconceptions.
First: "Lisp has no programming philosophies" and styles.
Not every program starts by zero. Since Lisp exists since the end 1950s, it has seen quite a lot in programming styles over the years and it may contain traces of several. Generally it may support more than one programming paradigm. For example during the Common Lisp standardization there was a wish to have a standardized object system. So instead of the multiple possible approaches (actors, message passing, prototype-based, ...), Common Lisp has just one: CLOS, the Common Lisp Object System. So, much of the object-oriented code written in CL is implemented in one particular object system: CLOS. Object Lisp, Flavors, LOOPs, Common Objects, and a bunch of other once had thus been replaced by one standard.
CLOS also defines a bunch of user-level macros: DEFCLASS, DEFMETHOD, DEFGENERIC, ... Everyone using CL & CLOS will use those macros.
Second: "every programmer becomes an island unto themselves". If we look at the way CLOS was designed: there was a core group of six people from three companies. Around that there was a mailing-list based communication with a large group of interested people. Early on a prototype was implemented as a portable implementation of CLOS. This was widely distributed among interested parties: implementors, companies, research groups, ... Then reports about the language extension and its layers were published, books were published, application & library code was published.
One of famous books coming out of this effort: "The Art of the Meta-Object Protocol". It contained also a toy implementation of CLOS in Common Lisp. Book and the implementation of CLOS (both the larger prototype and the toy implementation) showed in excellent quality how to write object-oriented Lisp code.
https://mitpress.mit.edu/9780262610742/the-art-of-the-metaob...
So, there are communities, which share code and coding styles. Not every programmer is alone and starts from zero.