From a startup angle, local news has gone broke because it is solving a problem that people have, but, critically, don't feel strongly about. It's not enough for a market to have a problem -- it has to believe that there will be an impact if that problem isn't solved quickly.
I'm not going to pontificate on whether people are dumber today than 50 years ago, whether people have shorter attention spans than 50 years ago, whether people care less about politics than 50 years ago. I don't know and, from a business perspective, the why doesn't matter.
Straight up, if you can't capture (ideally) your market's wallet or (less good) their attention, you can't monetize them. End of story.
That said, hats off to the Colorado news outlets still making a go of it and bringing local news to our state. Local news *is* the lifeblood of an informed and vibrant community, and we'll all lose if it goes away.