Another case of where because the better system is suppressed on the more common environment, We are unable to advance the desktop metaphor.
If I am fair I think lack of middle click paste is the main reason I don't enjoy using windows much.
I think it's great that there are 2 ways to move things around, but it does help a lot to be very clear on how both of them work, and some apps do things a bit differently too (eg Ctrl+C in Houdini can be followed by mmb in a terminal, which is a bit unusual, but ok once understood)
Emacs may use the term "yank buffer" globally. vim does not: in vim, they are simply called "buffers". There is a command called "yank" because it is bound by default to "y" but this command is not the only way to place text into a buffer.
https://www.oreilly.com/library/view/learning-the-vi/9780596...
In X11, the text goes into the "[Primary] Selection" or the Cut Buffer[s].
https://www.xfree86.org/current/xcutsel.1.html
CUT_BUFFER0 is the default, and obviously there can be more with higher numbers. But when you're pressing the middle mouse button, you're typically pasting the PRIMARY selection. There has never, ever been usage of "yank" in X11 documentation.