Why are engineers so bad at estimation? (medium.com)

Is anyone good at estimation? What professions? And why do we only speak of bad estimation when it is negative (i.e. over budget, late). To me being wrong on the other side (under budget) is equally worse, setting aside or acquiring additional resources for a project that were never used (lost opportunity, waste of money).

It's an estimate not a fixed point. Technology is continuously changing. It's complicated.