Clearly there is a lot of variability here – e.g. what profession are we talking about? What kind of physical and mental shape is the subject in? What exactly are they bringing to the table? Are they an asset to the workplace or have they become an anachronism? Are they bringing value or just bringing everyone down?
There is only one real protection from becoming a liability and ironically it’s the same thing for young people.
Your value must be undeniable.