Why does last-mile delivery optimization break down when moving from theory to real operations?

Why is last-mile delivery optimization so hard to get right in practice? That’s exactly the issue — the last mile is where theory meets reality. I found a solid breakdown here: https://twincore.net/blog/last-mile-delivery-optimization/ It explains that this stage is the most complex and expensive part of delivery, often taking up to ~40–53% of total shipping costs, mainly because of fragmented routes, individual stops, and unpredictable factors like traffic or customer availability. On top of that, companies constantly have to adjust routes in real time — almost 70% of them do it regularly, which shows how dynamic and unstable this stage is. So optimization isn’t just about planning routes anymore — it’s about adapting continuously with real-time data, better visibility, and smarter dispatching.