I'm curious about another question: "Why do so many people feel that email a) needs to and b) is perpetually about to die?"
Snail mail existed to allow people to send messages over long distances. You'd send a letter, wait, and hopefully get back a reply at some point.
Then came the telephone. The telephone let you instantly send a message using your own voice, and immediately get a response.
The telephone did not kill snail mail in spite of it probably seeming like a superior communications medium. Turns out there's a demand for passive, asynchronous communication. But then we got voicemail, which achieved those goals. Surely the snail mail killer! Except it wasn't. Then there were smart phones that could send text as well as other media. Certainly we can't possibly have a need for snail mail anymore -- except we do.
Email, if anything, is 'a new snail mail', and some of the things that keep snail mail around will keep email around for quite some time. There are generational biases towards email, it's entrenched in certain industries (like, say, the email marketing industry, but others as well), and it is well supported for different modes of communication, such as 1-to-1 or 1-to-many communication, you can send nearly any kind of media through it, it can be completely automated, and it's passive and asynchronous. It's checking more boxes than snail mail, which has been around for literally centuries.
In short, I don't think email is actually going to die. That's not to say it doesn't have issues. It has huge issues. Like, really big issues. Big enough that I do believe email will look very different in the not too distant future. It's actually evolving constantly, just very, very slowly. In ten years, there will still be email, but the issues of today will be long gone, which would be nice except we'll surely have wholly new issues to contend with. :)
The media culture tends to fan the flames of extremism, fanaticism, panic, etc. That's why there's so many Google results when you search for things like "Email killer" or "Email needs to die".
It doesn't seem super-likely to die, and being that the issues with it are addressable, there's no dire need for it to die that I can see.
I'm sure in the 1850's when London was going through rampant cholera outbreaks and the entire city stunk to the high heavens because raw sewage was floating through the center of it on the River Thames, someone probably suggested we just build a dam, fill in the river, and get rid of it once and for all. I mean, really, what could be a bigger nuisance to more people in that day and age? Instead, this really awesome innovation took place that made the river cleaner, the population healthier, and beautified the riverfront. It was the first sewage system. It wasn't glamorous and the inventor isn't a household name, but it shows what our species is capable of if we allow ourselves the joy of actually struggling with a problem to come to a solution instead of paving over issues, which we seem more apt to do these days.