I don't understand Neal Stephenson's books

Well, the Baroque Cycle and Cryptonomicon, anyway.

There are some very minor spoilers here but anything I mention is
given away in the first 100 pages - hardly the first chapter in a
3000+ page story.

The Baroque Cycle seems to be about the end of Alchemy and the
beginning of the scientific method and we meet some of the most famous
scientists of the time.  Then, along comes Enoch Root, who has a magic
potion or something that extends his lifespan tremendously.

I never was able to understand if this was an example of technology so
advanced it resembled magic or what.

I guess Stephenson doesn't need to have a Crighton-esce message or
meaning behind his story but I just found Root's character and magic
(aside from being very knowledgeble, he doesn't do a lot of magic or
anything) jarring.  Was he there simply for exposition? To explain
things to the readers?  Why have magic in a book about modern science
breaking away from superstition?

The title of this thread is misleading; I loved Snowcrash and found
its mix of ancient religion and modern computers and tech fantastic.
The copy I read was a loaner from a friend and I will probably buy a
copy for myself.  A better title would be, "I don't understand one
little part of Stephenson's books, but I bought more anyway".