AS various outplacement people explained: With a long tenure at a place like VZ, you end up earning above your true market value (this is on average of course, individuals will vary). If training has kept your skills up to date, you MAY be able to argue nearer the market, but it all depends on presentation.
As a made up IT example, if my day-to-day work has really been on legacy mainframes, but I've got AWS certifications via training, an employer may well still prefer some 25 year old who has been using AWS at a job for two years. You have to communicate that your overall experience is going to provide extra value to a new employer. And sadly, sometimes it really won't!