@ceilingroofgoat: Global rankings tend to be heavily if not solely research-focused, so they wouldn’t tell you much about the relative quality of the (American) undergraduate experience.
That said, you can quibble about whether UCLA or WashU is better, but it’s certainly no slam-dunk that UCLA is definitely better or harder to get in to (which was the crux of your argument) considering that, at the undergraduate level, WashU’s student body has higher test scores and a lower admit rate.