I don't use Ubuntu very much, but I have been testing it for approximately ten years.
There are some that are running their data centers off of Ubuntu.
Ubuntu Linux can be used for anything. Anything that you can do on Windows, you can do in Ubuntu. For example Microsoft Office, Microsoft is really famous for, their Windows platforms, and Office suite.
In the past, the open-source community had alternative software such as Open Office or even another project called Libre Office. These open-source solutions provided an office suite similar to Microsoft Office. However, with the new Office 365, you don't need Windows to work on Office these days. Outlook, PowerPoint, Excel are all web-based. You can run Ubuntu and open your Firefox browser and use it.