Haha. Let me provide a little bit of background, and the usual disclaimers that this is all just my personal take on it yadda yadda yadda.
I was a PM on the Web Platform team that is in the center of all this. The Web Platform Team is the one that works on EdgeHTML and Chakra. My area of focus within this was anything app related - PWA, Electron, React Native, webviews, and so on. This shift to using Blink and V8 is one that totally affects my team, and I helped educate our management on the pros/cons of making this shift. Similarly, a lot of people supported content around what a migration would look like for their respective areas (DOM, DevTools, Performance, Rendering, etc.), so it was a massive collaborative effort.
What I recommended matched my personal views: As a web platform, we have two customers: developers and regular consumers. The shift to using Blink and V8 is one that makes both of them happy.
Developers rarely tested for Edge, and our tools for making that testing even possible was significantly behind what Chrome and Firefox provided. Being tied to Windows (and the latest version of that for the newest features) made testing even more of a challenge for your typical web developer. If you were an app developer, especially one who used an Edge based webview in your app, you really couldn’t do much since your customers were on everything Windows 7 and up, and our webviews only worked on (again) the latest versions of Windows 10. This meant all “Win32/desktop” apps still used an older webview based on IE that had the widest reach.
On the consumer front, the story is much simpler. They don’t care what goes on under the hood. They just want their favorite web sites to work properly as the developer intended. Partly due to developers not testing in Edge (see above) and partly due to us not supporting the standards developers cared about, getting sites to function properly was an uphill battle. Our low marketshare didn’t help. (For example, less than .5% of this site’s visitors use Edge. I think @REB_412 was one of the few who tested in it, adding to the count :P)
Moving to a Chromium-based solution solves both of these problems directly. There will be areas where we are ahead, and those are places the team has openly stated their intent to contribute back to Chromium to make the platform stronger. I left the team by this point, so I have no visibility beyond what I read publicly on this.
Me leaving wasn’t directly related to this, but the timing just happened to work out. I was on paternity leave, and I had some breathing room to figure out what my ideal job would look like. I had been at Microsoft for 10 years at that point, and I worked on some fantastic teams (and some less fantastic ones), so I had a good gauge on what I liked and didn’t. What I liked shouldn’t be a surprise to most of you: it was a combination of working on challenging problems (that customers cared about) while working with designers, developers, and web technologies. I passively looked around and talked to a variety of companies. Through a combination of luck (all job hunts have a large element of luck in them!). me really enjoying the people I met during my interviews, and them liking me, I joined Salesforce as a Product Manager for their Lightning Design System
Feel free to ask me any other question you may have! If I can answer it, I will