Hi Piyush,
I’m sorry, but I do not have good answers to your questions.
Note that many students in Amsterdam are not at all interested in doing a PhD, and so the number of such students doing a PhD at UvA or a better institute may also not be that informative.
But I do know one UvA master’s graduate who recently was admitted for a PhD in Cambridge (after he was rejected by Amsterdam itself—there’s probably lots of noise in these decisions).
The programs in continental Europe (e.g. Amsterdam, Darmstadt, Tübingen, ETH, and Lausanne) are usually 2 years long and the UK ones (Edinburgh, Oxford, Cambridge, and UCL) take one year. I don’t know how well the UK ones adapted their program to online teaching, I have just heard that Edinburgh is currently struggling to do so.