Well, I don’t think it’s just about what helps me. I think it’s about the craft of Engineering, which is fundamentally about shipping things.

You can be a good coder but struggle to deliver because you get distracted or rabbit hole, over or under engineer, etc.

The engineers who have really mastered their craft have mastered not just the coding, the infra, operations, etc. they’ve mastered putting it all together and getting it out to the world.

The ones who have mastered all that can usually give pretty good estimates. The ones who haven’t usually find estimating to be difficult.

So it’s not so much that estimating is the single critical skill, but rather that estimating comes from a synthesis of all the other skills, and as a result it’s a good indicator for how much someone has mastered the craft.

Estimation effectiveness is inversely proportional to the intrinsic difficulty of the problem you work on. Being a programmer who is good at estimation is a bit like being a doctor with the lowest post-op death rates - it doesn't necessarily mean you're actually the best.