I think the opposite is really the case. Back in the day, fact checking was incredibly difficult. If you were a domain expert, you might notice something was o

I think the opposite is really the case. Back in the day, fact checking was incredibly difficult. If you were a domain expert, you might notice something was off, then go to the library to double check the information, and if the library happened to have what you needed you could try to convince your close friends and family of the truth. The other 99.99% of what you heard on the news or read in the paper was simply accepted as fact. Conspiracy theories were, at the time, either what the news said were conspiracy theories, or ideas so fringe that the news didn't even talk about them. Nowadays, we are a few thumb movements away from fact checking literally any piece of human knowledge. There hasn't been a sudden proliferation of fake news, it's just more readily apparent. As it has become easier to spot the holes in shoddy reporting, faith in journalistic institutions has plummeted. More people are getting news from alternative sources whose quality is variable. For better or for worse, there are simply more versions of stories nowadays. To try to retain viewers, traditional media outlets have tried to cultivate an image of themselves as the arbiters of truth which they once defacto were, and to do so have been quite liberal with labelling their competition as conspiracy theories. We haven't seen any uptick in the number of people wearing tinfoil hats to keep out the mind control rays or claiming any given senator is a lizard person. Instead, we live in a world where you're labelled a conspiracy theorist if you don't think there is a shadowy cabal of government agents spreading misinformation to manipulate us or depending on which of the past two presidential elections you think was illegitimate. Even small deviations from the narrative of any particular bubble are heretical, but that narrative, and every other one, is composed from the incomplete knowledge of fallible people, so invariably as time goes on you will start to notice inconsistencies in the story. In years gone by, we would have simply chalked this up to someone being misinformed, people could admit they were wrong and papers could print retractions and we'd all forget about it. But now the combination of the record being so readily accessible and the increased role of our media consumption in our personal identity means we have forgone nuance and are strongly pressured to adhere to increasingly absurd stories. It's so much easier to label the other side as stupid and crazy than to try to demonstrate the veracity of our position and face the fact that we are not entirely correct either, but if we do not strive for truth ourselves, it becomes easy for them to see the faults in our logic and further convince themselves that we, in fact, are the crazy and stupid ones. tl;dr there are many more non-mainstream narratives being labelled as conspiracy theories at the same time that the mainstream narrators who would normally dispel them are losing credibility.