Provided the manager only rarely exercises the power, and is open to being persuaded not to, having somebody able to veto risky dependencies can be really quite useful.

Normally when I'm the one with that power we rapidly get to a general understanding of what's small enough that I (a) probably won't care (b) will take responsibility for tweaking the schedule to makre time to get rid of it if I do.

And 'big' dependencies are generally best discussed amongst the entire team until consensus is reached before introducing one anyway.