"Fictional evidence" is, indeed, not evidence of the dangers presented in the fiction. But, in the aggregate, it is evidence of the common fears of the population

Yes, and I reckon it's biased evidence of those fears (and the fears in turn are biased indicators of real world importance).

I would say, then, that the proper way to interpret the washing machine by my heuristic is to look at it as something that takes people slightly closer to living the heroic/fun lives of the protagonist. The internet, by contrast, obviates the entire problem class of information deficiency.

Putting aside my quibbles with the heuristic itself, I think this still overrates the Internet, which fails to fill in information gaps as modest as "where did I put my keys?", and underrates the washing machine, which allows us to assume away an entire afternoon of drudgery each week or so. (In fact, household appliances in general can account for most of the 20th century rise in American married women who work, a truly massive social change.)