If you want to use a Portable OS, then create a Windows to Go version of Windows 11 with the help of Rufus and the steps mentioned here.

How to make a bootable USB drive If you're trying to install a new operating system or flash your BIOS, you're going to need a bootable USB drive - here's how to make one.

To kick off our Windows coverage, we’re taking a look at Rufus, a lightweight utility that makes it incredibly easy to create bootable USB flash drives. The weirdest name for the most useful ...

Perhaps they referenced this guide to create a bootable Live USB on Windows, allowing them to test drive something like Ubuntu without making any changes to their PC.

If you want to use this USB installer with newer Macs as they are released, you'll want to periodically re-download new Catalina installers and make new install drives.