Did KDE not have this before?

How to get this working now

(As multiple people didnt know that this already works)

PiP works and the windows can stay on top, but they don't by default, they need a kwin rule.

Search for that settings page in the menu and add a rule

• class unimportant
• window types all
• window title exactly "Picture-in-Picture
• force put window to foreground

The UI is weird because there is no clear distinction between conditions and actions, but it works, this one might be specific to Firefox based browsers though.

Anyone else having problems with PIP on Wayland? PIP windows simply refuse to stay on top for me (Pop!_OS 24.04)

How is this different than just having multiple windows?