I think you're confusing intrinsic and extrinsic motivations with willingness to work hard. You're ascribing a behaviour to a character trait or ability (a "type of person") that is IMO usually due to work circumstances (i.e. a situation that person finds themselves in, and well placed to exploit with the resources they have).

Working 7 days on extrinsic motivations is soul destroying.

Doing the same on intrinsic motivations is life affirming.

There's also different types of work. Manual labour can be done for long hours - if you're young. Mentally intensive work can be done briefly for long hours, but it rapidly stops working well. If you work is more about connecting people and motivating them, I think it's a bit more scalable, especially if you can feed from the emotional energy of interaction.