Because Microsoft builds Office 2019 as a deeply integrated desktop suite requiring strict activation and local registry framework, a "portable version" can only be created by third parties using application virtualization. These tools package the Office executables and their required dependencies into a single isolated file. While this allows the app to launch on a machine without installation, it bypasses official distribution networks. The Risks of Downloading Unofficial Office 2019 Portables
If you need to work on different computers but want to stay safe and legal, consider these alternatives:
The Truth About MS Office 2019 Portable Versions: Do They Work Without Installation?
This article covers the official story, the workarounds, the risks, and the best legitimate alternatives for those who want to run Microsoft Office from a USB drive or without installation.