That's a rather defeatist attitude. Perhaps be a bit more creative in how you ask the questions? Find new ways to interact with a more diverse group of people? Take larger samples?

Further, the media could refuse to echo consistently unreliable poll results. Ultimately the media loses when people can't trust what's being reported.

Right, but given how infrequently elections occur, how do you receive the feedback loop to iterate on your models? The reason why statisticians and ML folk like to get huge datasets is that it helps them refine their models. Elections occur every 4 years and often reflect very different political circumstances from previous races. Perhaps if we had continuous polling, then pollsters and models could become more accurate, but as it stands now, most of these models are based on historical data.