Polls are gamed -- why do we continue to rely on them?

We already know that Russian hackers were able to surgically target pro-Trump supporters to send them propaganda to turn the election, so why aren't we ready to embrace the fact that our polling companies already know what kind of answer they are going to get before they make a call? If anyone knows our political profiles, it would be the polling companies.

For example, according to this thread, the Republicans are experiencing an attrition of young Republican voters, which is the reason hardcore Republicans are unyielding in their support for Trump.

https://www.democraticunderground.com/?com=view_post&forum=1002&pid=10783949

So, I'm wondering, why are the polls surgically working around the attrition, and relying on answers from the hardliners? Isn't this going to over-represent the number of Trump supporters?

Why aren't we calling foul?