Come on, a problem nobody really had? I wholeheartedly disagree. Data loss and the orthogonal problem of lacking free space on computers is/was a massive problem at enterprise scale and OneDrive, for all its many shortcomings, is well and truly into good-enough territory to cover the 80% case. I'd go so far as to argue that the scenario you've described is by far the less frequent one. And if it frustrates you, you're afforded the ability to designate files and entire folders to be kept downloaded at all times anyway.