alt Hacker NewsAt least for Python (since I'm more familiar with Python code and the Python ecosystem): progressive typing lets you incrementally add typing to an existing Python codebase. So you can have at least some of the benefits of typing for new or updated code without needing to re-write in a new language.
Gradual typing is the worse of both worlds.
You get the complexity and slower development times of using statically typed languages along with the bad performance of using dynamically typed languages.