They developed software as "juniors" in companies—we just don't belittle them by calling them "junior devs".

Bringing in No True Scotsman doesn’t save the argument.

These people were exceptional outcomes, where luck and hubris met sufficient competency. You cannot argue the general case from exceptions.

If we view the person we are looking to hire as a "junior dev", a "junior dev" is what you will get. But if you seek a young, competent software dev—one you might find.