> That's because bias is at the root a social problem, not a technical one.

Bias is systematic error.

Maybe your thermometer just always reads 5° high.

Maybe it reads high on sunny days and low on rainy days.

Bias is distinct from random error, say if it's an electronic thermometer with a loose wire.

For classification problems, there's also this impossibility result: https://www.marcellodibello.com/algorithmicfairness/handout/...