Greg Esres wrote:

Of course, with GPS, the pilot can, and should be, the final
authority on the distance to the final approach fix or point.

Agreed.

However, this "service" provided by ATC occured (I suppose) long
before we had means to always verify the information. Seems a bit
unsafe.

Go back to TWA 514 in 1974 and they didn't provide much information at
all with vectors to approach courses.

There have been more unsafe situations resulting from vectors over the
years than anyone really knows. The NASA database is full of them, but
the FAA ignores the issue. Some are controller errors, some are pilot
errors, and some are a combination of the two.