> But it's not actually taken as a reference (with &) anywhere I see...
That is effectively what is happening internally. A string_view is morally a pointer/length pair; that pointer has to be initialized somehow.
> and even if it's just internally referencing the (static) string
It's not. The function call constructs a temporary std::string from the string literal, but once that is done the contents of the temporary are entirely independent from the string literal.