The problem with the idea that it is unusual that "everyone" on the internet has ADHD is that the internet (and especially people making comments/posts) is not a random sample of the population.

The internet is GREAT if you have ADHD and are trying to get a dopamine hit, which is pretty much the constant state of ADHD due to dopamine dysfunction. It's a fire hose of content and people to interact with. At any given moment I would expect a greater percentage of people with ADHD to be online than those without ADHD.

It's also worth asking, if fakers didn't exist would people with ADHD be treated any differently by society? There has been scorn towards people with ADHD as lazy or undisciplined for decades. It long predates the current widely viewable videos of people faking disorders for attention.