The British constitution (and where it is still relevant, it’s effects on the other Commonwealth Realms) is a pretty major hobby of mine. It’s not well understood even in the UK and the Commonwealth - one thing I’ve always admired is how many Americans seem to have a decent understanding of their Constitution and understand its importance. Brits - and others in the Commonwealth - tend to take ours for granted.
Well your common law, and written law predate King John I (King Edward forced to sign a doc those name I don’t recall, “liberties something” John forced to sign Magna Charta) so there a lot of law there. Our Constitution (and Declaration of Independence) are comparable recent and pretty much straight forward in it’s intention. Our courts have managed to make a mess of things but original intent is easy to understand.