I'd venture that certain [generally skeptical?] people find it easy to spot. So, disinfo is easy to spot for someone who makes it their business to spot it. I don't know the ratio of skeptical to credulous in the population, but from recent events it is apparently not great.

Ever wonder what kind of person responds to spam, such that there's an incentive to send spam? I have a friend who regularly asks me, "Hey, what do you think about [insert conspiracy theory]? Pretty crazy world, huh?" Then I ask, "Where did you hear that?" They say, "It's in the news!" I ask, "In the regular news? Or like, InfoWars." They say, "The regular news!" I Google it. The only result is a site even worse than InfoWars. I tell them that site is pure garbage, that the story appears nowhere in mainstream news, and if I can find a debunking I send it to them. This happens, like, biweekly.

This person is a highly educated, extremely intelligent, experienced professional. Not a rube. What's the difference between us? It's not that I'm smart and they're dumb.