Battlestations

Mostly the use cases. Barrier or other KVM-like solutions are great if you don't literally 'need' only an extra monitor attached to a single PC. The biggest workflow issues I see with vietual KVM's are just what I mentioned (maybe in an edit): one app on both monitors is a no-go, drag and drop files is annoying, but otherwise it's nice to be able to fully utilize the remote system.

It's different from VNC/RDP/etc in that it doesn't actually feed video anywhere. The remote system still has to be connected to an actual display, like a laptop's own display. So they're all kind of tackling the problem in different ways.

VNC/RDP/etc: allow full remote access to a computer that doesn't need a monitor attached at all. Barrier/software input: Only let you wiggle the mouse and hit keys remotely. (but it does work for the login screen on Windows and Linux if it runs at startup) Software monitor: Removes the ability to drive the remote computer and turns it in to a very power hungry monitor, but it's a direct display.

The remote desktop ones also 'can' integrate well with the window manager which allows them to know what parts of the screen are updating, and send only updated regions. They tend to be quite a lot less overhead than a constant video stream. Though with hardware acceleration these days, a constant video stream is less of an ask than it used to be.