Fantastic article. I was particularly interested because WordPress has been working to add collaborative editing and the implementation is based on yjs. I hope that won't end up being an issue...
It would have been nice if the article compared yjs with automerge and others. Jsonjoy, in particular, appears very impressive. https://jsonjoy.com/
The transport for collaborative editing in Wordpress 7.0 is HTTP polling. Once per second, even if no one else is editing. It jumps to 4 requests/sec if just two people are editing. And it's enabled by default on all sites, though that might not be the case when it leaves beta.
The transport is a completely different concern... (though there's also a websocket implementation).
They use Yjs: https://make.wordpress.org/core/2026/03/10/real-time-collabo...