Before we begin, there are probably a few definitions that need to be settled on.
"Geek" has moved from its origins as a noun meaning a lurid performer at a sideshow distinct from the physical freaks to meaning "an enthusiast in a specific field of interest". Somewhere in the middle, it was used to disparage people whose interests were considered below those of the socially well-adjusted. A "nerd" was someone of intellectual achievement, who may or may not have been geeky about his interests, but was certainly down a social rabbithole that predicted poor outcomes until his or her adult income allowed admission to normal society, but now it means a fashion choice consisting of piercings, blue hair and slogan T-shirts. Far be it from me to police the evolution of language, but this is a rather sad dilution of a term.
Now, you may say that society has changed and is more accepting of the sorts of people those words used to describe but that would be nonsense and I'm going to explain why.
Remember an old movie called "Revenge of the Nerds"? You will note the depiction of the nerds in question as being scrawny, embarrassing, socially awkward losers until they combine their brainpower to thwart their bullies. This is a typical underdog story that everyone can get behind (except maybe that rape scene). But what has changed is that now the prior domain of these nerds - the world of computers - is now so ubiquitous as to be an assumed, unavoidable facet of any modern individual's life. You're reading this using a computer.
The media has spun a narrative of how we're all geeks now, because
children's entertainment like Star Wars and comic book superheroes are
the mass juggernauts they are instead of the slightly embarrassing
secret adult hobby interests they used to be.
Except these are lies. Star Wars and superhero films have been literally the most mainstream form of entertainment that has ever existed since the late 1970s. Did you not know about all the box office records they shattered? The merchandising avalanche they precipitated? There has been no time in the last thirty five or so years that you have not been able to buy merchandise for these franchises, and the reason they have suddenly become so acceptable to adults is because the original target audience is now all middle-aged and has never stopped buying the tat.
What's really happened is that the rise of the marketability of these nerd/geek signifiers to an adult audience has allowed a certain type of vocal narcissist to claim nerdiness or geekiness as a sort of safely "oppressed" identity, primarily thanks to the prior idea of what they were without offending anybody of a sexuality or race that is genuinely at a disadvantage in current society.
So what happened to the real nerds and geeks? Let me tell you. You changed the words. Now they are "basement dwellers", "neckbeards" (or "legbeards" now too), "manchildren", "kidults" and a host of other targeted insults that it's unlikely that anyone else will claim as a fighting standard. They have no defenders and, to be fair, don't really deserve any. The old computer nerds are now the embarrassing denizens of the world of tech support that the rest of the computer-using office scorns as "weird" while constantly asking for help.
I don't care about these people, because they are generally almost as insufferable in reality as mainstream society has deemed them. I also really don't care about the "legitimacy" of the new geeks or nerds, because these terms are now utterly meaningless. And that's why you should stop using them and fighting over them, you fucking children.