"Browser-specific failures are the number of WPT tests which fail in exactly one browser." From wpt.fyi In other terms, WPT test failures for Safari means Safa

"Browser-specific failures are the number of WPT tests which fail in exactly one browser." From wpt.fyi In other terms, WPT test failures for Safari means Safari has bugs or unsupported features that both Firefox and Chrome do not have. As for Interop, it focuses on a specific, very limited areas, like "scrolling" or "subgrid" and is in no way representative of the overall feature set of a browser. So no, contrary to what you're implying, it's not that Chrome is too advanced, or doing too much, it's really Safari that is buggy and lagging behind both Chrome and Firefox (by a lot).