By 2015, we're talking about Windows Phone 10. After 7, 8, and 8.1, the world was pretty much done with Windows Phone. Microsoft pulled the plug less than two years later.
You could argue in a round about way they were killed because they didn't execute competently or something, but several things on that list were either outcompeted or obsoleted by their environment (Silverlight => HTML5).
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The problem most people have with Google is when products that are doing well and are well loved by many... but not up to Google scale standards
Wunderlist fits that description. They did replace it with To Do, which was made by the Wunderlist team, but technically not the same app
XNA does, but MonoGame picked up the slack
And of course... Microsoft Reader. That hideous Metro app that would try and open in full screen back in the early Windows Store days. Good riddance.
Then the iPhone 3G was released, and IMO that’s when iOS showed how wart-filled WinMo had become.
https://www.versionmuseum.com/history-of/discontinued-micros...
Microsoft Teams Progressive Web App https://www.versionmuseum.com/history-of/discontinued-micros...
And also, it list things that were consolidated into other apps, I don't know you could say it was killed off, but more moved. (such as Microsoft groups, is just a part of outlook now, and not a standalone app)