As one needs no more ability to get on the Internet than to turn on a television set, the intellectual capacity of most users is rather low.
To be offensively blunt, many persons who utilise the Internet have very little ability to research or reason so are available to be scammed.
Where television offers commercials so that you know something is being ‘sold’, Internet sites are jammed with Ads which seem information. These ads net money for the creator of the site.
As the creators of sites know they are dealing with a low I.Q. population they post whatever they think will get the most ‘hits’. They are paid by ‘hits’.
They look to see what is trending and then create a site full of rubbish that will be believed.
Right now, everyone will post about ‘cures’ for ‘Corvid-19’. These cures are rubbish. Those who post or invent these cures know they are rubbish, but they know people are stupid.