I'm a few months short of 70 and just published my 14th book, 9 of them on software development. I saw a tweet last year in which the poster said, "I suggested a Karl Wiegers book to someone and got called a boomer." He said it like that was a bad thing.

Some aspects of software engineering change rapidly (the cool language, development method, or platform du jour). Others change slowly (my primary field of requirements engineering). Breadth of experience, maturity, perspective, and collaboration are valuable contributors to effective software engineering, and most 25-year-olds don't have much of those yet.