> You can add multiple e-mail or contacts accounts (even from different providers) and it'll seamlessly merge them in the system Mail/Contacts apps - why can't we have the same for messages?
Because there are standards there - SMTP and MIME and HTML for email, vCard for contacts.
For the contacts app, whatever fun graph or RDF or whatever format you use for contacts, your extension has to provide contacts via the surface of the SDK, which luckily had vCard to influence it. That may mean that the contacts app cannot support round-trip edits of those contacts, and you need to go back to whatever source to change things.
Same with calendar events - applications can expose a calendar, but this is typically not editable and you need to go back into the application to change things (e.g. to remove a session from your calendar, go into the conference app and say you no longer intend to attend it).
The message apps typically have none of this. They don't have commonalities in terms of identifiers (and may all claim authoritative use of say a phone number, with no approval of the carrier). They have no consistency in formatting. They have a varying set of additional features, none of which are designed to be compatible (e.g. person-to-person payments in Facebook Messenger vs in iMessage). They may also support extensions by third parties, business accounts with custom routing and workflow, etc.
XMPP and later Matrix tried to create standards around this, and for XMPP there was a brief time we thought there'd be buy in by larger parties like Google and Facebook. I'm very curious to see if we see uptake in ActivityPub, or if the same product/market forces make its popularity transient as well.
Because there are standards there - SMTP and MIME and HTML for email, vCard for contacts.
For the contacts app, whatever fun graph or RDF or whatever format you use for contacts, your extension has to provide contacts via the surface of the SDK, which luckily had vCard to influence it. That may mean that the contacts app cannot support round-trip edits of those contacts, and you need to go back to whatever source to change things.
Same with calendar events - applications can expose a calendar, but this is typically not editable and you need to go back into the application to change things (e.g. to remove a session from your calendar, go into the conference app and say you no longer intend to attend it).
The message apps typically have none of this. They don't have commonalities in terms of identifiers (and may all claim authoritative use of say a phone number, with no approval of the carrier). They have no consistency in formatting. They have a varying set of additional features, none of which are designed to be compatible (e.g. person-to-person payments in Facebook Messenger vs in iMessage). They may also support extensions by third parties, business accounts with custom routing and workflow, etc.
XMPP and later Matrix tried to create standards around this, and for XMPP there was a brief time we thought there'd be buy in by larger parties like Google and Facebook. I'm very curious to see if we see uptake in ActivityPub, or if the same product/market forces make its popularity transient as well.