What is the Value of Browser Diversity?

In May 2019 I attended a talk by Mike Taylor who works on webcompat at Mozilla. Mike told the sordid story of window.event, a non-standard IE invention that was replicated in Konqueror, which showed up in Webkit, which stuck around in Blink, and was now Mike’s problem in Firefox. It was a good story fraught with ups and downs and literal “Breaking the Web” level changes for a tiny feature rollout.