Because we buy the games, the microtransactions, the cosmetics, etc. Even just one purchase multiplied by millions is a win for publishers. Whales and content creators fuel the cycle even more. Meanwhile, currencies get deliberately convoluted: you need stars for a pull, which require sparkle farts, which you can’t buy directly or in exact amounts. Out of sparkle farts? $14.99 gets you 6000—enough for three whole pills! Don't worry, there's a pity system, so the most you'll spend is only $400. And then you're left with 60 stars, and if you just had 40 more!
You’re not forced to buy, but they make the grind brutal and a slog. If you're really unlucky, it can even make actually playing the came harder. And as long as this system makes money, it won’t stop. Games are turning into storefronts with a mini-game attached. Good games feel like rare blessings, and creativity is often found only indie studios. Big teams have talent—they’re just not allowed to use it, their companies don't care about that. Gotta make money, more money, all the time, forever, or you've failed.
~~I say "they" like I don't play a few gachas myself, but still.~~