Is that true about Fortnite? You don't get any competitive advantage anywhere from spending money? People are paying billions just to get different clothes on their character?
No. Fortnite battle pass is a bundle of cosmetic items within a season, most of which you will need to unlock through gameplay after you purchase. Players are essentially signalling they’ve paid the fee and spent enough hours to unlock some skin or emote.
Battle passes in most games just give you a series of exclusive cosmetics to grind. And are time limited to urge you buy it sooner, and play more to grind it before it's over. Or you can spend more money to skip the grind.
Hacker News strongly underestimates the appeal of cosmetics.