I think we have to be honest that the state of the art for end to end encryption doesn't work well yet for many types of usescases beyond 2 way communications.

I think we have to be honest that the state of the art for end to end encryption doesn't work well yet for many types of usescases beyond 2 way communications. How could you make an e2ee calendaring service? E2ee google sites like page with groups based access control? Realtime group collaborative editors? Any one of these features is distinctive and novel enough that if you had something that worked even in a moderate scale you could turn it into a company.