Comment by upofadown

The killer feature here is efficient handling of very large groups. That's great but that isn't the main issue with this sort of thing.

Identity in end to end encrypted group messaging is hard to do. This seems to leave the difficult identity issue to future work. How do we know that we are due to have a breakthrough in the near future?

Even if they do come up with something usable in a technical sense, there is no way you are going to know who all the participants are in a large group. The problem is to some extent inherently unsolvable.

Interoperable 1 to 1 end to end encryption might be a better first try.