Elections are like measuring the temperature of a sample by measuring the energy of each molecule in the sample. However, there are other ways of measuring temperature that don’t require that detailed information, and they are the ones actually used.
Many elections don’t provide any information not already known by the polling organizations. If the gap in the polls is large, 10 or 15 percentage points, it is very rare that they are wrong.
Lots of elections are essentially useless. For example, there is no reason for Wyoming and Vermont to hold presidential elections. Each states 3 electoral college votes will go to the Republican and Democratic candidate respectively. In the rare case where they would not, the winning candidate would have won a huge landslide in all the less partisan states.
The uselessness of elections is also recognized in many local races, where one party or the other simply does not run a candidate.
“Many elections don’t provide any information not already known by the polling organizations. If the gap in the polls is large, 10 or 15 percentage points, it is very rare that they are wrong.”
That assumes that the polls are honest and competently carried out.
So many polls today are push polls, not so much to measure the actual “temperature” as much as to make you believe what the temperature is.