Great link, just the type of thing I was curious about, thanks.
In regards to the content:
Point 1 is a bit exaggerative, maybe more so in 2021 when everyone is familiar with the concept of “adding a friend”.
Point 2 is no longer an issue due to iOS allowing third party keyboards now, which could potentially be used as a workaround to “programmatically send messages” AKA automatically alter the content of the message before it’s sent or delivered.
Point 3 is valid, SMS and MMS generally suck.
Point 4 is just a recap of the other 3 point and therefore not convincing.
So, would Signal - or TextSecure - take the same approach in 2021? I’m not sure.
Also, I’m not convinced Signal’s reasoning from moving away from a public protocol is exactly pure in nature. Like I said before, of course the private channel is more controllable, more profitable - so Signal was incentivized from the get go to make that change.