i think britain keeps the monarchy out of tradition more than anything, and how exactly would britain go about telling the old farts that they're no longer royalty?
Unless they all tragically died in the same freak accident and the government of britain decides to just discontinue the monarchy altogether, I think they're stuck with them
I wouldn't settle for anything less than a rusiian revolution style bloodbath. say what you want about the russians but they know how to handle a royal family