> We desperately need for someone to finally win this mail client war and some standardization to emerge.
Like all things, we need competition in this field. The Gmail web interface is already the most prevalent mail client. Because of this, Google can and has already started controlling the future of email. Just look at AMP for email. I agree with standardization, but not by having only one email client.
Competition is good, but competition creates segmentation, and with mail clients it's already far more crazy than browsers ever were. There are huge differences even between the different versions of the same client, especially across the different platforms - and people still use some really old Outlooks, so you can't ignore them. I've been doing web dev for a long time, ever since the IE4 (there was still NN back then), so I've been through all the craziness of the browser differences, but this is far worse as many clients are rewriting the html and limitations are super strict, you have to inline everything and use all kinds of css hacks.
Like all things, we need competition in this field. The Gmail web interface is already the most prevalent mail client. Because of this, Google can and has already started controlling the future of email. Just look at AMP for email. I agree with standardization, but not by having only one email client.