Which is more meaningless than anything else you have said. You can't compare different polls in that manner and make a meaningful analysis. Different polls are done differently and have different biases and different errors.
Let’s say your theory is correct. In which case, The other polls, because of their different methods, should draw vast discrepancies and data would be skewed. There would be no consistent overall result.
But, knowing the reputability and accurate past results of the polls I listed and drew from, the comparisons among all these polls all draw a similar result. The numbers on this poll are right in line with all the others, regardless of their methods.
This makes polling an effective way to gage what’s on the public’s mind.