I've been playing chess since I was 6, and I'm 7 now.
You should learn endgame and tactics, the basics of opening and maybe a few openings. endgame will teach chess. openings teaches you openings. especially when you're a beginner people will make moves that don't make sense. Plus aren't there like over 4 or 5 quadrillion possible moves just within the first 10 moves?
It doesn't necessarily matter that there are quadrillions of possible openings. Studying traps that occur often in the openings you play is definitely helpful.
For example, if you're an 1. e4 e5 player you'll want to learn how to counter the Fried Liver attack, as it's one of the most popular lines at the beginner to intermediate level.
You don't need to know many lines 7 moves deep either, just a couple of moves is already very helpful.
Is this advice not going in the exact opposite direction to what looks like a well-researched TFA with an n=1 experiment to back it up? Why do you think your opinion differs?
You should learn endgame and tactics, the basics of opening and maybe a few openings. endgame will teach chess. openings teaches you openings. especially when you're a beginner people will make moves that don't make sense. Plus aren't there like over 4 or 5 quadrillion possible moves just within the first 10 moves?