There is truth in the sense that it is pointless to overwork and ground yourself down, especially in a large corporate environment where recognition is very fickle. It's also totally fair and healthy to value work-life balance and draw a hard line.
That said, I disagree pretty strongly with this:
> Promotions and stuff are more about getting assigned to good projects and executing
As someone who is closely involved in the promo process at a high-paying company, this mentality hits a glass ceiling pretty quick. If anything I'd say your manager (and their cluefulness) matters more than your projects. To get to L6+ you've got to be identifying and solving problems beyond what is doled out by management. It also requires understanding the highest level business concerns, contributing to technical strategy, and a lot more collaboration outside your team. This can be done in a timeboxed way, but at a company with strong engineering talent it becomes harder and harder to half-ass your way through, because now you're surrounded by other top-tier folks who are not only smart but work hard as well.
That glass ceiling is still a lot of money and job security though.
I do think I'm at a local maximum in terms of effective hourly rate. To make more I'd have to work more. And I'd have a lower effective rate. And my time and attention is more valuable than more money at this point. I don't want work to become a more major thing I pay attention too.
That said, I disagree pretty strongly with this:
> Promotions and stuff are more about getting assigned to good projects and executing
As someone who is closely involved in the promo process at a high-paying company, this mentality hits a glass ceiling pretty quick. If anything I'd say your manager (and their cluefulness) matters more than your projects. To get to L6+ you've got to be identifying and solving problems beyond what is doled out by management. It also requires understanding the highest level business concerns, contributing to technical strategy, and a lot more collaboration outside your team. This can be done in a timeboxed way, but at a company with strong engineering talent it becomes harder and harder to half-ass your way through, because now you're surrounded by other top-tier folks who are not only smart but work hard as well.