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.
It would have been nice if the article compared yjs with automerge and others. Jsonjoy, in particular, appears very impressive. https://jsonjoy.com/