It "done" really, and I can use it today knowing its pros and cons. It would be "dead" if it had a glaring flaw which couldn't be fixed (which I don't think mutability is)

Every project has cons and they should embrace it and call it out like this project did instead of forever targeting a perfect library but nothing is perfect. It serves its purpose.

I am not sure if they are telling people not use it just because chrome now says to exclude it or they came up with it independently.