A device that reads high today and low tomorrow is worse than one that is slightly offset but stable. Here is how we design for consistency.
For home users, the value of a reading comes from the trend, not from a single number. If the sensor drifts between units or between weeks, the trend is unreadable no matter how good the datasheet looks.
That is why we select components for stability in real conditions, calibrate the analogue front-end as a whole, and sample every production batch against reference instruments.
A slightly offset but stable device supports decisions. An unstable one does not, whatever its spec sheet says.
