Debian is the classic server Linux, but tends to be the second choice on desktop hardware. It'd be wrong to write off Debian ...
Whatever the case, a portable Linux installation on a flash drive can be used in place of a normal storage drive in your PC.
However, if you put a portable Linux installation on a flash drive, you can carry your own operating system with you wherever you go. Most of the time it is as simple as telling the computer to boot ...
If you're looking to migrate from Windows 10 or 11 and Linux is in your sights, you might want to try one of these desktop environments to ease the transition.