There are anecdotes about amazing contractors who can work 8 hours a week showing up pointing out problems and offering smart solutions but almost all of them can do that because at some point they were putting in 100 hours a week.
If you care about moving upward yes you will need to do more than show up for 8 hours.
Upward, yes. The top, no
>If you care about moving upward yes you will need to do more than show up for 8 hours.
This is not true. If you need to show up for more than 8 hours at the bottom to move up, then you are working at a place where it is expected you will show up for more than 8 hours once you move upward. In my experience, there are companies where almost everyone does 8 hours or less, and there are companies where the work never stops. It's an office culture and it doesn't change with titles, from my experience.