Can a household robot provide as much utility as a car? If "yes", the market gets pretty big.
I pay $200 every 2 weeks to have a 3000 sq ft house cleaned.
That's about $5200 a year to fully clean a house. And it's a human, so they can also tidy up, clean out the refrigerator, do my laundry, water my plants, etc.
I'd gladly pay or finance a robot that could have dishes clean, laundry folded, and carpets vacuumed by the time our family got home.
They only became a “necessity ” once they went mainstream and the world started evolving with vehicles becoming a part of everyday life.
I can certainly see the same thing happening with residential robotics.