What 'experiences' have you had that have made you anti-monarchist, IDN ? Bitten by a corgi? Backed one of the Queen's many losing racehorses?
As to not being able to replace her, have you considered what happened to James II ? He was de facto removed by Parliament, driven into exile, and replaced by a King and Queen, not themselves prime candidates in the bloodline, who were more to Parliament's liking and who were made to sign up to various terms severely restricting them and their successors, which terms still apply. If that could happen in the c17, how much more could a fullly elected House of Commons achieve now, should the electorate demand it?
Indeed, Edward VIII was removed, but to what extent that was reflecting the will of the people is debatable. It may have been the "wisdom" of those in power that dictated that.