So why not just use OSC 52, which is built into most terminals? The functionality required already exists.

Yes OSC 52 is very handy for vim over SSH: instead of X11 forwarding - you can just yank text from remote vim into the local clipboard using OSC 52 [1].

Overall it's much quicker - as yanking in vim with X11 forwarding and '+clipboard' sometimes had a delay.

(ps: I think OSC 52 is implemented in xterm and URXVT, but not yet in gnome-terminal)

[1]: https://github.com/ojroques/vim-oscyank