In early English, the “uu” paired letters were quite common in spelling words, so much so that in writing them they were often squished together for clarity. They were meant to sound as “ooh-woo” when written together.
As English evolved, the four peaked “u”s written together became more and more written closer and evolved into our modern three-peaked letter of “W” named “double-u” … but in medieval times pronounced with a decided “HW” sound of a sibilant “Hwoo”. In fact, our modern “wh” words were once spelled “hw” for a spell (pun intended), thus later resulting in “awhile” and “while” having similar meanings, with the first retaining more of the leading sibilant “h” sound. Some accents in the UK still retain the lifted beginning of the “wh” in “who, what, where, when, why” that gives them a lilting cadence.
Names such a “Guuilliam, Guuindolyn, Guuinovere or even Uuilliam” were common before the multiple peaks of writing double-us started confusing reading, espeacially when mixed with “i” (Look at the number of potential peaks in “Uuilliam”—8!). Counting the peaks got confusing, and figuring out where to cross the “t” or dot the “i” made combing the four “uu” of the three of “w” a no brainer.
That’s why there are so few “uu” words in the English language…
I say let's start spelling “who, what, where, when, why” "hwo, hwat, hwere, hwen, hwy". Or have I missed something? Maybe I just don't know how to talk correctly. Should I be saying "w hoo, w hat, w here" for example?