It doesn't matter. The top 1% of a large pool is still bigger than the top 1% of a small pool, so competition increases for the same number of jobs.
For top US firms, it may well be that there is a better pool for top talent, but not THAT much better. I believe it would be possible to do inferences from # of non-US citizen in FAANGs.
There is no way you can filter out top 1/100 candidates anyway.