Or stated another way, adding block scoping necessitates Python 4. You could be cheeky and make it work in a backwards compatible way by adding new opt-in synta

Or stated another way, adding block scoping necessitates Python 4. You could be cheeky and make it work in a backwards compatible way by adding new opt-in syntax but it wouldn't fix match nor be terribly ergonomic having to declare it all the time.