This sounds like something a soviet comission would declare after an accident. What went wrong and how was it corrected? You needn't know, it has been corrected.
More importantly, there are explanations from pollsters about what they changed and they speak openly about remaining possible sources of uncertainty/error. See e.g. the quotes in this article: https://www.newsweek.com/how-pollsters-changed-their-game-af...
All of this is a quick google search away, and anyone who has actually paid attention to polling knows exactly how polling has changed in the past 4 years. It's literally impossible to read anything on this topic without knowing that polling firms openly talk about methodology changes. Therefore, your original comment was either intentionally misleading or profoundly uninformed.
NB: You can absolutely agree or disagree with their methodological choices, especially around "shy Trump effect" and whether Trafalgar-like "what do your neighbors think?" questions make sense.
But even if you disagree with their choices, _it's plainly untrue to say their attitude is "you needn't know". To the contrary, they're quite open about how their polling methodology has changed._
Are you willing to defend with evidence and reason your initial claim that pollsters haven't explained what they have/haven't done to try and correct polling methodology? Or are we just going to name-call like we're 12 year olds on a playground/irrelevant partisan zombies in the internet comment section?