Except with Microsoft browsers, the populace has decades of conditioning telling us "Internet Explorer bad, need to install my own browser." And when Edge came out, everyone just continued what they were already doing. When Edge came out, it also had serious issues with media playback at times that reinforced that decision to many.

The power of the defaults is not overrated. This is just an excellent example of an "exception."

In the case of Google, they already have decades of conditioning with people viewing it as the main or only search engine worth anything. When you need to look up something, most people would tell you to "google it." The power of the defaults benefits google.com much better than it benefits Microsoft with browsers.