I almost agree with you, but there's a qualitative difference between obsession and focus just like addiction vs. dedication.

Focus/Dedication is something you can choose to do, it's a tool you can use (though some people's tools work better than others). When you need to stop you can and then move onto other things.

Obsession is something that controls you, you are the tool being used, and when it's time to move on the obsession continues to control you keeping you under its thumb.