The question is a bit broad to give you a precise answer. I often cross check multiple sources for a given topic and I find the sources most frequently identified dismissively as the mainstream media does a pretty good job of getting the facts of the situation correct and complete. I have not in my personal experience noted this being meaningfully different in the 22 years of being an adult whereas I have noted in that same time frame the explosive growth of social media and person to person sharing of made up news and fake takes that used to proceed far more inefficiently via email and subsequent radicalization of America.
Keep in mind that I don't just mean right wing kooks. Crazy people come in all stripes and while different camps may not agree on much what they all share is a pride in being in the know. Of being more plugged in by virtue of knowing about for example conspiracies that are somehow simultaneously secret and available via the feed of people you wouldn't trust to watch a hamster.
It used to be that merely being available say on TV or in a widely distributed newspaper was a good first pass filter because it filtered out most obvious malarkey. At the dawn of the internet this increasingly ceased to be so as it became easy for anyone with an increasingly broadly available skill set to reach a wide audience if what they want to say resonates with what people want or worse fear is true.
At least however because making a nice website was harder it was at least SOMEWHAT easy to pick up on the bunkum because it looked like junk and was hosted on geocities. Now one can really and in fact be plugged into a lot of really high quality and up to the minute data on social media and in fact it all looks the same whether on twitter or on slick easy to make websites and we are relying on people with no usable first pass filter to pick out the garbage based on critical thinking skills they in fact lack.
I think its well established without further need of proof that people trust the media less. I suggest its because a lot of people are building their world view on complete nonsense not because the media is any better or worse. This seems trivially true from observation but I don't know how to go about proving it to you in the large.