Ron Natalie wrote:

I don't know how it happens, but the requirement is that they're
supposed to notice whether I have arrived at my destination not
whether I was handed off by approach. This means one of two
things:

1. Tower must tell the system that I've landed.
2. Tower must tell the system that I haven't landed.


1. Tower is part of the system.
2. Tower sees you land.
3. The system knows you landed.

1. Tower doesn't see you land.
2. Tower calls you on radio.
3. You don't respond to tower.
4. Tower initiates search.

OR

3. You respond "missed approach".
4. Tower says "contact departure".


OR

Several other variations. The point is no action is taken by the tower
to cancel an IFR flight plan for a landing aircraft because there
simply isn't any action that needs to be taken.