When was the last time you looked into servo because this is dated at best, bordering on misleading. The js support has increased massively over the past year with things like intersectionobserver, shadow dom, and dozens more apis. Stylo supports many newer and advanced css features, of note recently is grid support. And the frontend servoshell has taken urls for a rather long time. If you try it out today with experimental features enabled you’ll find that most websites mostly work.