One of the questionable benefits (for UK pilots) of JAR is the relative ease by which JAA approved pilots from over the EU can pick up UK jobs - such as the KLM Cadets picked up by Ryanair recently.
This will make getting a job after the current crisis is over more difficult for
UK fATPLs than it was after 1991 because
of the greater competition from type-rated multilingual pilots from e.g. Swissair Sabena
Alitalia etc etc