Be careful since it is a double edged sword. Device bound session means the browser has the capabilities to differentiate devices, and thus can be used for more accurate tracking information. Of course I'm not saying it is not useful, having created a fair share of websites myself, I know the pain of authentication on the web and how it can be challenging to secure from tons of possible attack vectors. And in my experience, the weakest link is always the user.

This is an incredibly important step forward but I have to wonder why its taken this long to come up with.

That took forever to implement, almost as if someone had stake in not doing this

Isn't this what WebAuthn already does? Why introduce a new protocol when another one does the job well?