I think signal is really only missing usernames (which should come soon) as far as features are concerned. And sadly, I don't think it will change much. I think signals problem is not really feature wise but adoption wise.
Signal needs more marketing. It needs a bigger user base. And I honestly don't know how to change that. Maybe some really top notch marketing strategy, with beautiful diagrams and text of some made up scenarios explaining the perils of using Instagram and whatsapp..
This is honestly goals. I don't have a partner but I dream of this. This is better than sex in my opinion.