TIL that trained monkeys are used to pick coconuts, since they can pick up to 1600 coconuts per day, compared to 80 for a human. However, there have been accusations of abuse against the monkeys.
In theory, humans have the capacity to consent to the work, find alternate work, receive actual wages for their work, and go home at the end of their shift
As long as the monkeys are fed and well cared for and not forced to work I don't see an issue. We use dogs for jobs all the time, cows and horses, even rats.
Just trade the monkey some sort of small reward for each coconut si ce it will prefer that over a coconut. Then provide regular meals and mental stimulation after "work hours". They should be able to choose if they want to go fetch a coconut for a reward though.
Slave monkeys are used because they're cheaper than the cheapest human labour in those countries. If you think any of the amenities you describe are available to these monkeys, enjoy your delusion. These are slave labour camps, and the monkeys are typically chained to the trees and physically abused if they don't gather coconuts. Dogs, horses, and cats enjoy a fair amount of protection from human cruelty in North America. Unspeakable things are done to the other non-human animals you mentioned