How long will the British monarchy last?

The popularity of the British monarchy ebbs and flows waxes and wanes, much of it based on celebrity value and revenue from tourism potential. As a system of government it has ceased to exist and is now totally irrelevant. So, will this archaic institution continue into the future in its present form or will the British people replace it with a less expensive means of attracting tourists to Britain. The French have done so and the royal palaces have been preserved and are open to the public. In fact, Paris without the Louvre would not be Paris. So, is the future of Buckingham Palace to be the same or will the present occupants continue to hold on to it as they do at present?