If there's no continuity then... what's the point exactly? Reset buttons are my ultimate pet peeve when it comes to narrative devices. It just makes it harder to care or be engaged.
There's more to continuity than B follows A. As others have said the point is telling a story that's entertaining. Check off continuity boxes isn't entertaining. In the end it just bogs things down.
So, JJ, make me change my mind. But don't insult my intelligence by calling it a multiuniverse. Just say, these stories happened when Kirk was young. That, I may be able to accept.
How does calling it a "multiuniverse" (or multiverse) insult anyone's intelligence? The concept has been a SF staple forever and has been used in Star Trek from time to time.