One doesn't even have to look that far. They haven't shipped a Windows update on time for years due to bugs pushing the dates back. I can't imagine that their backwards compatibility requirements have been part of the problem. In fact, wasn't there a specific issue that was linked back to compatibility with CP/M not that long ago?

Edit: This is what I was thinking of: https://www.itnews.com.au/news/how-a-1974-bug-still-bites-wi...

That is not a counterpoint, just a downside (which can be offset taking several approaches).

I would like to see a comparison between recent versions of macOS and Windows 10.