Yep, to add to @prezbucky’s point:
The academic strength of undergraduates in the US goes deep and the academic strength of the faculty goes extremely deep.
As a comparison, because the very top is full of smaller privates and tiny LACs in the US and the US is a big country, if you add up all the undergraduate places in all those 30 colleges that I deem Ivy-equivalents, that number still is a smaller percentage of the population than Oxbridge+LSE+Imperial offer in the UK, UTokyo+Keio+Waseda offer in Japan, and the Grandes Ecoles offer in France.
And because the elite privates here admit holistically, there is a ton of talent spread out all over (compare with the UK where by almost any alumni achievement measure, Oxbridge are far ahead of any other UK uni besides LSE).
Faculty talent is spread even further down in this country. I don’t think it’s an exaggeration to say that the US has at least half of the entire world’s top academic talent. The US has the vast majority of the top 15 spots in the ARWU research rankings, the clear majority of the top 50, and a little over half the top 100 in the world.
A run-of-the-mill state flagship will likely feature greater faculty talent than the top university in most of the other countries in the world.