@dHeinemann one at my work has over 100. Some absolutely idiotic consultant told them to split Sitecore features by project. They’re all deployed at the same time to the same place.
There’s rarely a good reason to split into multiple projects unless they’re going to deploy independently. When that is the case, there’s usually an explosion of projects to support the separation. There’s no harm in that, but there’s overhead for the developer to find things that should be avoided if possible.