The default KDE font is Noto Sans, which is a professionally designed font commissioned by Google and is used in various Google projects, including ChromeOS.
Noto Sans is a "version" of Arial and is inappropriate for a user interface.
I have looked at screenshots of ChromeOS and, for obvious reasons, they don't seem to be using it - they use Roboto and Product Sans just like they do in Android.
I have looked at screenshots of ChromeOS and, for obvious reasons, they don't seem to be using it - they use Roboto and Product Sans just like they do in Android.