For a long time Guido wanted CPython to remain simple, as the reference implementation.
Probably also during the 2 to 3 migration, but that goal appears to have now been abandoned.
I wonder how the authors of other implementations like pypy will be able to keep up as the reference implementation becomes more and more complex.
> the reference implementation.
The problem was he exposed too much of the implementation into the language itself, destroying its ability to be a simple reference implementation that others could re-implement.
That question is already answered. pypy only supports 3.11 today and is largely unmaintained.