My dad worked as an engineer in the same firm for 30 years and retired. The company was founded before his father was born, and was publicly listed before he was born.
Substantially every company I have worked for didn't even exist 30 years before I joined, let alone before I or my father were born. Most won't be around in 30 years.
Several employers nearly went out of business, had substantial layoffs, or went thru mergers that materially impacted my department/team/job. The guys at the very top were always fine, because how could the guy in charge be responsible?
Even within the companies I stayed 5 years, I had multiple roles/bosses/teams.