Somewhat agree, as our planet has cleared it's orbit of any debris local to our path around the sun, and that is one of the defining characteristics of a mature planet. But as for objects on eliptical orbits, there are still plenty out there that cross our path that we have not "cleared", there are hundreds of thousands documented. Also, lets not forget that long period objects from the Kuiper belt or even possibly the Oort cloud that may only cross our path on long period orbits once every hundred thousand years or more are still out there. We see and discover new long period objects quite frequently that no living human will ever see again. Not to mention other objects in the asteroid belt, Kuiper belt, and Oort cloud can collide and send stable objects into entirely new orbits.

So yes, the VAST majority of objects have already been cleared by our planet, or gobbled up by Sol or Jupiter, but there are still plenty of them out there. And to this day, the Sun and Jupiter take most of the impacts from the objects that do get sent into the inner solar system, but there are still plenty that cross our path. Space is a pretty big place so the odds are low, but there are still risks.

So I agree that MOST of them pose no real threat, but wouldn't agree that ALL of the ones left pose no threat. The dinosaur extinction is still linked to an impact of some kind, and that was only 65 million years ago. Granted that seems like a long time, it's really not on the scale of the ~4.6 billion year lifetime of our planet. 65 million years ago the planet was still 4.6 billion years old.