I think by the time you are hiring people at 27 years old or whatever, there is a noticeable gap in motivation. A quarter century of lived experience (which is "inherent" to the person you're hiring) is a lot, especially at the beginning of one's life.

There are all sorts of things like depression, cynicism, past experiences, etc. that can lead to someone have a lower baseline of motivation. It's also highly contextual, which I think is what you're saying and I 100% agree with. Some people thrive in role A and would want to bang their head against a wall for 40 hours in role B. Others vice versa, others would be meh in either, etc.