The 8.0.2 documentation includes this statement:
"If UUID values are generated by an application (as opposed to the server),
the values must be inserted as UUID strings and converted using strtouuid().
Attempting to insert binary values directly may result in values colliding
with those generated by the server or another system."

Why is that? If I have a UUID in my program space, held in a binary type,
why can't I insert it as-is, just like I would a blob?