If you allow the notion of client to include "web browser driven by humans", then what is it about Fielding's dissertation that is considered so important and original in the first place? Sure it's formal and creates some new and precise terminology, but the concept of browsing was already well established when he wrote it.
It formalized the network architecture of distributed hypermedia systems and described interesting characteristics and tradeoffs of that approach. Whether or not it did a GOOD job of that for the layman I will leave to you, only noting the confusion around the topic found, ironically, across the internet.