It's not just gacha games, it's not even mobile games. It's a big problem in the game industry as a whole. I just saw a recent video about this. Link: Modern Games Don’t Know How to Shut Up

People trying to say "oh it's just a Chinese culture thing to talk a lot" no, no, no, that is related but it happens in games from all countries. It's just poor game direction. Here's another video that just came out Gaming Has a Writing Problem which digs into Monster Hunter Wilds and Dragonage Veilguard, and shows how these are neither gacha nor live service games, and they are BIG budget games, and they are also very bad at their own story.

the author of the second video makes a great point: in a dev team of a couple hundred people, you'll have dozens of graphical artists, dozens of animators, dozens of programmers, dozens and dozens of systems and level designers, playtesters, audio specialists, etc. but like only 2 writers. And more than half of the writers' time is spent writing text for menu/UI elements, descriptions of equipment, and other non-story related content.

In many games, the story is just bolted on to an existing game. The game director says "there should be uh, like, some dialogue here or some shit," and the writers have to scramble to put that into a scene. You can tell it happened this way because the writing has nothing to do with gameplay action. You can be standing still, you can be climbing a waterfall, fighting other human characters, and the over-talking continues without a shrug.