That's pretty easy to define. An addiction is something that you want or feel you should quit or tone down, but don't have the self discipline to do. A hobby, even an obsession, is not an addiction. And similarly it's entirely possible to become addicted to "productive" things, like work.

The Bezos-like individuals who have no lack of money yet still work relentlessly, even to the detriment of the other factors in their life, are a dime a dozen. And a person of his sort saying he wishes he could work less hard would be seen as little other than a humble brag, even if he may mean it absolute and desperate earnestness.

And getting slightly philosophical for a moment, I doubt there's anybody on their deathbed that would regret spending as much time as they did doing the things that they enjoyed, unless those things started to themselves cause even greater problems. And a playtime alone does nothing to inform one as to the chances of the latter. For some, 5 hours a week might start causing problems - for others 60 hours a week would be perfectly fine.