For veterans engineers that might be true. But for a junior engineer pre-AI, velocity has always been technical. I know junior engineers who after a whole year of writing C++ still does not grok std::unique_ptr; and this person consistently has the least velocity on their whole team. When I used to write performance reviews for junior engineers, their performance really was dominated by their velocity, which was roughly measured in lines of bug-free code written within a time period. A good junior engineer would be given a clearly defined feature and write good code quickly, whereas a worse junior engineer would be given the same thing and write code slowly or write buggy code quickly that required so much work debugging and rewriting.