The main things that come to mind are:

- Encyclopedic scope but enormous attention to detail;

- eclectic and exploratory approach to organization;

- highly individualized prose style;

- significant amount of authorial distance, almost mystery (is the name a pseudonym? where do they live? why are they so interested in catnip anyway? etc);

- no fixed point of completion, everything is constantly being revised;

- subscription-based fundraising model (Patreon is far from new in that regard).

Burton's The Anatomy of Melancholy is probably the best example I can think of that illustrates what I like about books from that period: https://en.wikipedia.org/wiki/The_Anatomy_of_Melancholy

Montaigne's Essays and the works of Robert Boyle and Margaret Cavendish are excellent too though, if you're interested.