If a hundred billion people have lived…
…and each of them has created, in their heads, their own version of their parents, siblings, and significant others—and make no mistake, that’s exactly what we do!—then fictional characters definitely outnumber real people.
Of course if you add the requirement that the fictional creations must have been written down, much less shared, then we’re probably back to ‘real people outnumber fictional characters.’ But don’t try to tell me that the Boss (or Mother or Uncle) you have in your head actually is that person…