Among the caveats, though, is the fact that the guaranteed traffic separation works great with IFR aircraft, but not so much with VFR aircraft. On top of that, even those who always fly IFR must be in VFR mode at certain times, e.g. to depart and pick up a clearance, or to cancel IFR at or before the final landing phase. Even if you had those protections all the way in, though, you could be left to your own devices if VFR traffic conflicts occur. And they do.