[ZeKK14]

Passenger planes make many flights per day, thus a lot of attention is made on the costs of usage (ie, the plane is not cheap to buy but it will be cheap to operate per flight).

Cargo plane fly mostly twice per day (base to sorting center and back), so they use older planes. They use more fuel per mile, but acquisition costs are low.

You can't just repurpose brand new planes for cargo use, it's not economically viable.

Plus, it would mean the safety of cargo pilots is less important than the safety of passengers...

[lwf]

Sadly, at least in the US, we have lower safety standards for cargo than passenger aircraft.

For example, crew rest requirements adopted in 2010 don't apply to cargo: https://ttd.org/policy/ensure-one-level-of-safety-for-all-ai...