Most finance decisions die in transit. The payment batch waits in an email the approver opens after the cut-off. The question about an invoice goes to whoever might know, bounces twice, and comes back half answered. The team talks in Slack all day, but the decisions that move money live somewhere nobody is looking.
Nance moves those decisions into the channel. A payment batch arrives with everything you need to judge it, and your approval in the thread is what releases it. A question about the books gets an answer with the underlying entries linked, not a screenshot from memory. A daily summary tells you what was handled overnight and what is waiting on a person. The work itself happens in your accounting system, with every action logged. Slack is simply where you see it and where you say yes.