Spot on. Something as open, ubiquitous, and deeply integrated into society as email is cannot die at the hands of a new proprietary chat platform.
We’ve had vast improvements over physical mail (email being one) yet physical mail is still deeply integrated into society. Even as letters have decreased things like packages have increased.
I don’t think email will ever die because it is not simply a platform that can be replaced by a competitor: it will require a shift in thinking, deep integration, and a low barrier to entry.