Nowadays there are no tastemakers, and thus you need to be a public figure in order to even find your audience / niche in the first place.
That's always been the case depending on what you're trying to do, though. If you want to be Corporation Employee #41,737, or work for the government, you don't need a "personal brand"; just a small social network who knows your skills is good enough. If you're in your early 20s and trying to get 9 figures of investment in your AI startup, yeah you need to project an image as Roy from the article is doing.
It's amplified a bit in the social media world, but remember that only ~0.5% of people actively comment or post on social media. 99.5% of the world is invisible and doing just fine.