It would appear on this forum that the people most bothered about this "shortage" are those retired and no longer in the job.
They seem to be the same ones bothered about changes and advances in technology and procedures.
Meanwhile ATCOs are moving more traffic than ever, with less staff than before and just as safely (if not more).
Things never stay the same, in any profession. Some German cars are no longer made in Germany. Nottingham Forest used to win European cups...