You’re putting words in my mouth. I never said pure-Python packages are trivial. On the contrary, also many pure python packages will have to figure out if they were reliant on some locking somewhere.
With respect, this is utterly unrealistic. Users will be battening down the doors of any project that doesn’t want to support nogil to add support for it. This is why I had proposed to just call it Python 4 and don’t mess around with the opt-in. It’s a false choice IMO, but has a very real cost in distribution complexity (building everything twice, interoperability etc.)