The only reason I got Signal to catch on with friends & family was that it made group chats between Android and iPhone just work for everybody. Although if they had already been using Whatsapp it may have been a harder sell. But Signal was easy to use to figure out.
This is a good question. What will the new bar be once the current “old people” are gone?
Maybe the trope would be people who are too busy to fiddle with settings, like a super busy CEO or something.