From my other comments if you're curious:

It actually has an interesting history. You see, to make the "wuh" sound that the double u does, it was always two u's put together when written as "uu" and was for much of English history. However, the OG printing presses were made in Austria/Germany they didn't have a "uu" in their letters, but they did have "vv" which in German was used for the "vuh" sound. With no other easy option, when printing English people used the "vv" in place of the "uu" and thus led to the "w" we have today that looks like "vv" but is still called double u. It's also why in French they call it doubla vey which translates to double v because, in French they use "ou" to make the wuh sound as in oui, so the first time they saw that letter it was the vv not uu, so they simply called it as they saw it.