But as to your point, on the roles and responsibilities of managers and engineers, I mostly agree with your comment about the role of a manager, which as I said before should be responsible for working with the engineer both to show their impact, but also making sure they're actually doing impactful work.
I disagree that if it's your job as an engineer to show what your impact is that you'll come up with creative ways of doing this. You can try to come up with creative ways of showing impact, and maybe a promotion panel will agree with you, but maybe they won't and you'll be left without recognition (I've seen this happen before).
To your last comment about competent engineers, I don't know what company you work at, but at mine, shipping projects on time, and under budget, especially when they are large in scope and involve complex technologies or large teams that you've led, and especially when those projects have impact on the company's bottom line, those project are considered major impact and and those engineers are amply rewarded.