As a USAian, I say we don't need 'em. I've never
heard one of my countrymen express any such yearning.

Of course the Royals we're most familiar with
are those of Great Britain, which in this era have
no real power, other than that of exasperating the
public* (alternating with entertaining them) so perhaps the hereditary feature wouldn't do all that much harm.

As to the entertainment value, if it were to be a
hereditary position the American people would get bored
and want to change the channel.

*Charles, for example

Dave Oesterreich