The hard reality is that the House of Saud is the ruling dynasty of Saudi Arabia. Throughout Islamic history, many powerful Muslim states were governed by dynasties. The Ottoman Empire, for example, was ruled by the House of Osman, while the Mughal Empire in India was established and governed by a hereditary dynasty. The Abbasid Caliphate and the Ayyubid dynasty likewise were also ruled by the families.
The important point, IMO, is to distinguish historical debates from the political reality of 2026. The House of Saud is the internationally recognised ruling family of the Kingdom of Saudi Arabia, and there is no internationally recognised rival government claiming sovereignty over the country. Saudi Arabia is a sovereign state whose government maintains diplomatic relations with countries across the world, including Pakistan and Iran.
It is also historically inaccurate to portray the Saudi state simply as a creation of the British. The Al Saud have a much longer political history in the Arabian Peninsula. The First Saudi State was established in the eighteenth century and came into conflict with the Ottoman Empire, eventually being defeated by an Ottoman-Egyptian expedition in 1818. They have had a long struggle against the foreign invaders (including Ottomans) until the Saudi Arabia was established in 1932.
From a Pakistani perspective, the more relevant point is that Pakistan deals with the government of Saudi Arabia as the legitimate government of a sovereign state. Diplomatic agreements, official visits, economic cooperation and security relations are conducted on that basis and it doesn't matter what some terrorists in Yemen think about Saudi Arabia. The main ruling government of Yemen align with the Saudis.
What matters to me that the Houthis must stop attacking oil facilities and Saudis or face the consequences and in that case they will be treated as a terrorist organisation, not the legitimate ruler of Yemen.