The big difference is that Python 3 was still CPython going forward, there was no one left to fork CPython 2 into an incompatible direction. Or like Wayland an

The big difference is that Python 3 was still CPython going forward, there was no one left to fork CPython 2 into an incompatible direction. Or like Wayland and X.Org Server. Quite different than an alternative that comes out of nowhere, expecting users to migrate.