> People are doubtful that the agent will be able to complete the task properly.

You answered your own question.

I do not trust an agent to give it unsupervised access to my systems.

If I had a completely local agent that was fully sandboxed and I would be willing to put data in the sandbox, give it a task, and come back later to see what it did.

I would not trust agents to run unsupervised with similar restrictions.