I think it's more it's an SMS replacement or extension, which is supposed to be an open protocol, and they're not opening up the API to support the additional e

I think it's more it's an SMS replacement or extension, which is supposed to be an open protocol, and they're not opening up the API to support the additional extended features (which is something out of Balmer/Gates era embrace and extend playbook, "we'll extend JavaScript, but you'll need IE to use any websites using the extended features and the site features will be broken without it" which is an anti-competitive practice that breaks what are supposed to be open platform independent protocols). Do something new, sure, extend features of an open protocol, sure, but if you're going to communicate with other Messaging platforms as a feature, you need to allow other messaging platforms the option to support those features on their end as well. Such as encryption, the ability to add emojis to a comment, full size attachments, etc. Signal is actually removing SMS support, so problem solved on that end. But Signal can be installed on most platforms anyway, so if someone wanted to participate in the extra features, they always had the option of simply installing the client app. I can't install iMessage for Android if I want to be in the family group message and not see "Mom liked an image" 15 times. I personally dislike iPhones, but I still want to participate in my family's group chat, Apple doesn't give me that option. At least with WhatsApp, Signal or whatever what phone we have doesn't matter and we don't have to join the walled garden to use really basic features. I don't know what phone my friends in Signal group chats or WhatsApp use, because it doesn't matter. If you're going to bridge different platforms, allow the other platforms to update to support it. It is exclusionary. Apple does this with FaceTime, I have my family install Duo/Meet on their Apple phones because I have to explain to them I don't have an Apple device for it, or if I do, its my work machine. At least that's a little less hostile than, "you can chat with your family but you're going to see activity you can't participate in".