Your second point is also true about wanting to get easier shots. But that also has little to do with the bonus because if you get fouled driving, you almost always go the line whether you are in the bonus or not.
Basically there are benefits to driving (getting to the foul line, getting easier shots, getting teams in foul trouble, etc.) and there are benefits to being in the bonus (going to the line on loose ball fouls, fouls holding on screens, fouls 30 feet from the basket, etc) but those benefits are almost mutually exclusive. Being in the bonus doesn't really make driving any better.