Vacuum cleaners and stairs

When I was hoovering my stairs recently, I took this photograph because I remembered a cartoon from a lecture in architecture school.

The cartoon showed a stairs and a hoover or vacuum cleaner which reached halfway and an exasperated housewife.
The question the lecturer posed was - which comes first - the length of the stairs or the length of the cable / hosepipe of the vacuum cleaner? Maybe the point he was trying to make is that architects can't be responsible for everything; the cart does come before the horse. Or maybe he was trying to suggest that a socket point halfway up a stairs wouldn't go amiss - if designers of electronic equipment can't be trusted then the architect should provide solutions for the domestic delight of housewives.
When I did a google search of "cartoon vacuum cleaner stairs", I didn't find the image I remembered but I did come across this ingenious solution!

A backpack vac.