Locally hosted models for an entire organization means having to hire people to install and troubleshoot the LLMs. You wouldn't want the employees to goof around unmonitored, so the LLMs would need to be centrally located and accessed through an internal portal, which means buying a couple of GPUs. Besides that, there's something to be said about having a company to blame if things go wrong, as opposed to blaming yourself if there's an issue.