Actually, the problem is not that IE has vulnerabilities, or that M$ won't address them. I noted very carefully Caballero's attitude due to M$ indifference:
Caballero has not reported the bug to Microsoft ... In addition, Caballero has also discovered lots of security bugs in Microsoft's newest browser, Edge ... some of which Microsoft addressed, but others didn't.
Two major problems exist in the interweb world. IMHO the major is the increasing and unecessary complexity of browsers, but nearly as important is the unbelievably low standard of web construction. Yes, the internet is founded on a long-dead paradigm of trust, but we do have W3C standards to mitigate that legacy--if site owners were prepared to pay the inevitable and amortizeable price of to-standard construction, and maintenance. We look around the webverse, it resembles a battlefield. The list of what would be prosecuteable catastrophes in the real world is 'way too long. And now we see that every single Yahoo account, 3 milliard (3x10^9 of them) has been compromised.
Will we see browser publishers held to account? Will we see site publishers held to account? I'm not holding my breath.
FWIW, I tried Chromium. Like I tried FF. One had an unfortunate habit of telling me what sites I could visit--when it could actually get out of the computer--and the other won't let me lift the hood. When the reflexive answer to any problem at all was "Clear the Cache!", I reflexively uninstalled. And the list of Chromium-base browsers is getting far too long--I miss the Presto engine.
I use IE11 because it will render any site in the webverse. Not always well, but useable. And yes, with security caveats. I prefer K-M because it is--with config and prefs tweaks--simply the most secure browser available. And possibly the fastest. But it does break some sites.