Design teams build the model and produce the plan sheets from it. Contractors use models to find clashes between trades before installation.
Example: a mechanical contractor and a plumbing contractor overlay their models. The overlay shows a duct that runs through a drain line. They fix the route before either one installs.
Most bids still run on PDF plan sheets and the spec, and those are the contract documents. If a model comes with the packet, check what the documents say about relying on it. Read the spec for any BIM duties your trade must price.