@SuperSenior19 Actually British students generally find the UK admissions system fair, even if they are unsuccessful in getting into Oxbridge, because they know it is simply looking for the cleverest students. Niall Ferguson described it well in an article I quoted here:
http://talk.qa.collegeconfidential.com/united-kingdom/2131394-oxbridge-admissions-criteria.html
Many people are willing to say that US admissions are biased in favor of someone else and/or against them. Almost no one says that in the UK, they’re just upset that they weren’t smart (or well prepared) enough.
And it’s strange to ask “who would want to take a test where even fewer people get top scores” when many applicants to elite colleges do things like AMC/AIME etc which are precisely designed to identify the very best students in a way that the SAT does not.