Andrew Sarangan wrote in
. 158:

So why does the AIM say that you can be cleared for the visual
approach if you have the preceding aircraft in sight?

ATC must provide separation between IFR aircraft. This can be done by the
aircraft reporting and agreeing to maintain visual separation, by radar
separation, or by nonradar separation if there is no radar coverage. With
dozens, or even hundreds, of aircraft lined up for landing at a major
airport, getting the other aircraft is sight is often not a problem. At an
uncontrolled airfield in the boonies, it might be, and it appeared to me
that they were too far apart to see each other in the OP, thus center has
to protect the airspace for the aircraft on the approach.

--
Regards,

Stan