funnily enough i was working on apps that did this back in the mid 00s. it was horrible. the standards simply couldn’t keep up. the clients couldn’t keep up. in the end it was better for the end user not use those standards and instead we rolled our own.
could be different story today but i don’t think so. just the video call feature would be an absolute mess to standardise. hell, even emojis would open up a can of worms. payments between contacts? contacts themselves? i fear this would end up being the mid 00s again.