[Thriptic]

Because then they might take excessively long breaks and get paid for not working. It would be extremely difficult to audit time spent working while being plagued by inefficiencies vs time spent messing around. Paying per delivery aligns incentives and is easy to audit. It also incentivizes truckers to push on dock workers to be more efficient which is in the entire supply chain's best interest.

[noobermin]

You can make the same argument against paying developers a salary. Ditto on paying managers a salary.

[Thriptic]

Yes you could which is why you have contractors. However, it turns out that with "creative" work it's a lot harder to implement that payment model without having an incentives problem.