Your question certainly goes to the heart of this excellent story and what Bradbury has achieved by it. Note how at the beginning the house is presented as a complete organism that ironically does not need humans at all to keep on functioning. Robotic clocks carry on announcing the wake-up call, mechanised kitchens keep on churning out meals and the house robots clean and maintain it every day according to a strict schedule:
Out of warrens in the wall, tiny robot mice darted. The rooms were acrawl with the small cleaning animals, all rubber and metal. They thudded against chairs, whirling their moustached runners, kneading the rug nap, sucking gently at hidden dust. Then, like mysterious invaders, they popped into their burrows. Their pink electric eyes faded. The house was clean.
Bradbury thus emphasises the state of technological sophistication that mankind has reached in this future world. However, it is incredibly noteworthy that this story is probably one of the few I have ever read that does not have any human characters in it. The minds that designed such incredible technology are all gone, the only momento of their existence is the "five spots of paint" on the wall marking the members of the family whose house is the focus of the story.
In addition, let us not forget the massive irony of the title of the story. The poem that gives the story its title is all about the ephemeral nature of humanity, and how we are temporary in the large scheme of things, and how, when we do eventually die out, Nature will "scarcely know that we were gone."
Thus, through irony, Bradbury points out that technology can be dangerous in making us think more of ourselves than we should, and ignoring our fragile and transient state as beings on a planet. All such technology is very laudable, but let us not forget that the same minds that made robotic cleaning mice also made atom bombs capable of wiping ourselves out so completely.