There are no lifetime guaranteed jobs. That is a peculiar idea that might only apply to being "born to farm your patch" in history at all. Institutions and entire job categories go away.
Collective bargaining is OK and not usually conflictual outside down cycles or downsizing legacy industries. The conflict narratives appeal far more to general consumers. Working class hero is huge in American history for both good and ill.
Where many unions go bad is running interference on liability, incompetency or even criminality. That is not unique to unions but suffers embarrassing large scale instances (cops? teachers? auto workers who stole tools).
These are tough things to get right. The battles for enough and fair (predictable is a giant issue for service workers) overlap with battles that should never be waged and mostly lose.