I work in a place where we have (former) COBOL developers and the actual mainframe. One co-worker worked here for 25 years until they retired last year (does it sounds like trade union propaganda already?). We also have a lot of 20 years old for whom it may be the first job.

Somehow it's consistently no drama and no nonsense place. Compared to the frat house atmosphere of the usual tech startup, it's really different.

Both my previous and current employer have some long-serving staff. One was incredibly effective because he effectively carried the entire oral history of the software system; it would have been a massive loss if he'd ever quit for some reason. Not even a union position, just has to be a "normal" company doing the normal thing of selling a product and/or service to customers rather than a stockmarket rocketship or a consultancy bodyshop.

These places do exist. They are very nice.

For some reason they always seem to be privately owned by one person rather than publicly traded or owned by a corporation. At least in my experience.