There's no need to paint typing as a black and white picture. Basically all of the major Common Lisp implementations are compiled yet allow for typing in order

There's no need to paint typing as a black and white picture. Basically all of the major Common Lisp implementations are compiled yet allow for typing in order to let the compiler emit better machine code (e.g. the compiler doesn't need to insert runtime type checks or use generic arithmetic when adding two u16s and storing the result in a u32). It's nice being able to use dynamic types for prototyping then gradually adding types later for better optimization by the compiler.