I really don't understand the qualms with SMS support. SMS was never secure, and it certainly doesn't become more secure when you push it through a pass-through on one app or another. There is nothing you can do to SMS to make it more secure except to send encrypted strings: but then you have the same problem of sharing secrets, etc. that requires a separate app to manage anyway.
It means I need an extra app now. Signal replaced my SMS app. I'm not going to stop using SMS completely, so if Signal drops it I need to use one more app.
And one that I have been able to happily ignore for years because Signal handled all my messages. If you are not a long-time Signal user then maybe you don't remember how they made a big song and dance out of offering this feature in the first place to make Signal more usable and accessible.
Because I already have an encrypted messaging app. It's called Whatsapp. This bumps up to E2E encrypted if both people using "SMS" have signal installed. Now this is just an alternative to WhatsApp. I will just keep using WhatsApp.
