Company-wide, it is used a lot for flow charts. From an IT perspective, we use it quite a bit for network diagrams and documentation. The Human Resources team uses it for organizational charts.
In terms of deployment, we have a kind of mixed deployment. I tend to use an on-prem version that is loaded directly on my machine. We are all Office 365, so a bulk of our users use it as a cloud-based downloadable solution, which is a part of their Office 365 implementation.