Yes, your avocado's have to be delivered very time-sensitive. But coal, oil, soy and most other bulk not so much.

In fact, due to price-fluctuations, ships delivering bulk goods sometimes deliberately slow down their route (but I cannot find the incident where and when this was reported anymore)

Edit: three guys I know, operate a sail-powered cargo service [1]. Time is a factor, not because clients require speedy delivery, but because paying three sailors for 2 weeks on-board is more expensive than 3 days. They deliver e.g. chocolate from the west-indies to Amsterdam with their boat.

[1] https://fairtransport.eu/nl/tres-hombres/