I wonder how many Switches are replacements. Even lowballing hardware failure rates, you get around a tenth of current Switch sales being replacements if half of the consumers are willing to purchase it again (which seems reasonable in the absence of market alternatives or a successor).
How much would poor handling at the hands of children influence these numbers is anyone's guess, although the number of original Switches should be at least 100m because otherwise MK8 would have implausibly high attachment rates.