You get the credit for your achievements. As you get to do everything , you are the only one who gets credit for it. You can’t end up in a situation where others do less, but get praised.
It’s easier to concentrate, focus. You’re interrupted less and don’t need to shift and shape around others. Sometimes group work is less productive because of too much gossiping and chattering. It’s more fun, but less work gets done.
You’re in charge of your goals and decide what to do and when. Your responsibilities might be allocated by someone else, but you are the one who decides who to deliver and carry out your tasks.
You get to make your own decisions!