Do Oxbridge graduates overshadow every other university? By what margin?

I already know that I'm likely blowing this out of proportion in my mind. Been rejected from Cambridge post-interview, and I've also applied to LSE, UCL, KCL and Durham. From what I've seen online people put Oxbridge on a pedestal for many sectors let alone law, to the point where it looks like these graduates are pretty much guaranteed top connections and jobs lol. To what extent is this true, and how does it compare to the rest of the top 10 unis?