Don't belive the hype - email was, is and will be the most popular tool for digital human to human communication

Yes, WhatsApp and other messagers are very popular today (year 2017).

Nevertheless I think email will be the future for digital human to human communication.

Yes, current mobile messangers are far more easy to use.

My question: How can we get email to the same (or better) level of usability?

Why is the current progress to increase mail usabilty so slow?

No advertising - no money.

I see no big improvement during the last years. Thunderbird and k9 exist.

But why do people prefer mobile communication apps?

Here are random list of thoughts, which I would like to see improved.

Thunderbird. Sending mail on slow internet connection: Sending takes "ages". In my case today, storing the mail in the IMAP-Sent-Folder took long. Why does this get done synchronous? It would be great of this could be done in the background.

Mailinglist. Creating group communication is far more complicated in email (compared to WhatsApp). AFAIK this would need improvement of the current protocols/RFCs.

Status and Status-Image. AFAIK this does not exist for mail up to now. I guess solving this is not possile with current hardware, since the underlaying problem is not turing complete (this was a joke).