I agree. A lot of new additions to C++ make coding with it simpler, not more complex. However it does mean there's more to learn, because the old style of the language still exists and is still accepted by the modern compilers as opposed to say, Rust which removes replaced language features when it releases a new edition.

Language, not libraries.

Editions are rather limited in what they support.

Try to design a crate that stays compatible across editions, while using libraries that have changed signatures across editions.

The crate itself keeps its own edition fixed.