At a large financial institution, self hosted sync is the only viable to use a tool like Obsidian. It could be a direct replacement for things like Confluence. However, enterprise level security requirement really will stop any company to even think about using a third party store for data. So +1 for a self hosted sync solution.
Semi-related – what is a realistic limit of collab team size? Can one vault one sync support a business unit of 50 people?