This would be a compelling article if the underlying premise weren't so wrong. Polling has never been more accurate, and the 2016 elections featured a historically low average absolute error. The 2016 national polling zeroed in on Clinton by 3 in 2016; she won the national vote by 1. For the "predictors" of the world and their moving needles, it was a colossal miss. For actual pollsters, it was within the margin of error and we slept the sleep of champions.

You do make some good points in here, but I can assure you that my brethren and sistren in the polling industry are way ahead of you in testing and modeling to adjust to change--as we do every year. The 2016 elections have caused a lot of people to cry out "What Happened?" Polls are not what happened.

(For context on the increasing accuracy of presidential polling, Pew has a great chart here: https://www.pewresearch.org/methods/2019/11/19/a-field-guide-to-polling-election-2020-edition/ )