But, still, Microsoft's browsers still aren't good. In my workplace (where we do some complex cross-browser work) they're an enormous nuisance to development and QA. I wish Edge were far better than IE, but they're both quirky. Firefox and Google Chrome ordinarily work predictably. Safari has a few quirks, Edge is really quirky, and IE is a narrow gauge steam train, all different.
Why doesn't Redmond stop throwing good money after bad and just license Firefox? Are they stuck in the sunk-cost fallacy?