I’d guess it’s just a result of the UI icons all being the same color (gold), 2-D, and minimalistic, abbreviated, symbolic, caricatured artwork representations of the actual items.
During Tech Stress, I always had to inefficently stop and think about the icons before pressing them to make sure I was clicking the correct one. Lumber camp and mine were particularly problematic for me
For me it had nothing to do with icon position relative to AoE2’s or the buildings’ appearance in viewport, but those could be improved… it was all about icon appearance