Look, the biggest difference between (and I'll use these phrases for ease of reference, but I mean good schools in the US and UK) the Ivy League and Oxbridge is 1 thing: money.
Oxford has been around for 900 years, how big is its endowment? £6 billion. That is risible. Some guy wrote a check to Stanford a few years ago for $1.1 billion on a random Tuesday.
What does money get you? Opportunities like you wouldn't believe. It buys the best buildings, the best facilities, the best dining halls, labs, professors, study abroad facilities, you name it. At these schools, they have people to walk you home at night if you're at the library too late and you don't feel safe, OK?
Have any of you been to a college at Oxford or Cambridge? It's like you walked into a dorm room in the 1970s. They are faded and tired, as is their mediocre faculty. Anybody good left for the East Coast around the turn of the century.
So, yeah, if you could afford it, anyone in their right mind would send their kid to the US and to an Ivy. If you can't afford it? If you loved your kid, you'd remortage the house, as my father did for me.