The UK is a bit of an exception through, large parts of Europe have gone though at least some sort of revolution or a change in constitution in the last century

The UK is a bit of an exception through, large parts of Europe have gone though at least some sort of revolution or a change in constitution in the last century, if not multiple. And the UK constitution isn't entrenched. Whenever the House of Commons wanted it to change to fit with the times it could be done. Imagine if the US constitution could be changed by a simple majority in the House of Representatives.