Eh. Dragon still has good material on pipelining and local dataflow analysis frameworks. The version two stuff on bdds is the most poorly aged part, IMO.
You can't take seriously a book which spends half of its pages talking about lexing and parsing.
It's the book from the times when single-pass compilers were a thing, and that's what it's about, a primitive single pass compiler. The field has advanced too much since then.
Things you wont find in dragon book: type inference and modern type systems, modern GC implementations, exceptions and error handling, modern register allocations and optimizations, modules and parametric modules. Seriously, a book spends 300 pages on parsers and 4 pages on type inference and unification.