This question already has an answer here:
How do we know that the observed location of a electron (or any quantum object) is purely random (there is no way to predict it) within the probability-function instead of normal randomness (we don't know how to predict it)?
As an analogy if someone would only be able to measure the amount of people (amount of electrons) and their individual IQ (location) he would see a perfect distribution (obviously only if he has enough samples) within a specific range (probability) and each individual measurement seems purely random (QM-randomness). He would then assume that their IQ is purely random as he has just not enough knowledge to prove otherwise (he hasn't spoken to any of them, hasn't analysed any in respect to education nor has he analysed their DNA).
Could the same be happening when we observe electrons or have we proven that their location is purely random?