Zillow deserves a fair share of the blame because they prominently feature a single number with dollar-level precision and bury the caveats multiple clicks away on a separate page.

Some basic UI changes could avoid all of that: e.g. instead of showing $123,456, show a range like $115,000-135,000, and keep the last few digits at zeros based on their estimated error rates. Similarly, their graphs could use shading to make it clear that they're showing the mid-point of a range rather than a discrete value.