Raedwulf wrote: I've never understood the point either of having an elected powerless HoS or of a second HoS that isn't powerless

Look at what's just happened in Italy for the benefits of a separate HoS.

Today's Observer has a piece about the powers of the monarch over legislation:

A series of government memos unearthed in the National Archives reveal that Elizabeth Windsor’s private lawyer put pressure on ministers to alter proposed legislation to prevent her shareholdings from being disclosed to the public.

Following the Queen’s intervention, the government inserted a clause into the law granting itself the power to exempt companies used by “heads of state” from new transparency measures.

Queen lobbied for change in law to hide her private wealth

Private Wealth? Ridiculous.