And it's not what you know that matters for fame, it's how good you are at selling yourself. Well, either that, or you get very lucky and the media picks up your story.
You can see a possible example of a genius getting media coverage in a niche area by looking at Kaze Emanuar and his Super Mario 64 mods. He's basically the best programmer for the system in the world right now, and has almost singlehandedly moved the community forward on every technical level possible.
His works also get a ton of coverage.
Yet I had never heard about him before. And while I could find a hackaday article, I didn't find anything more mainstream. So I would estimate that 99.9% of the population will never hear about him.
Could the 'mainstream' media cover every genius or great creator? Probably not, there wouldn't be enough room. There are so many great people creating works and making discoveries that you likely won't ever know about more than 1% of them, at most.
It's hard for me not to think that the kind of people who write what you just wrote think of themselves as the superior ones. And that's an instant turn-off.
Influencers with no factual knowledge but a strong opinion gather eyeballs and sell ads much better than a scientist with a nuanced opinion and a difficult niche topic to talk about.
It also doesn't help that the general public in the west is somewhat hostile towards the idea that other people might be a lot more intelligent than they themselves. It's like the temporarily embarrassed billionaires, but for IQ.