Whee, more long posts!
Now I've never properly played gachas outside of PGR and the discontinued SMC, and I despise defending the genre in general, but to expand upon FluffyCow:
Next time you're on the bus or train, look at what people do on their phones. If it isn't antidemocratic brainrot asocial media, it's games, and yikes are those horrendous. Everything's full of ads, multiple psych PhDs worth of manipulation and both P2W AND P2P mechanics at once.
Now compare this with popular gachas. You get to play 99% of the game for free, have a continuos stream of new content, side-activities/minigames and story. Do you really mind that there are skins 60 chips each? That in order to be in the top 100 global leaderboard (which is just bragging rights) you need to spend the price of a car? Ever more so since so-called "triple-A" games just do the same thing but with a 100 chips fee up-front. They've normalized lootboxes in SP games for crying out loud!
Most of the big-name gachas allow you to drag along just fine F2P with daylies/weeklies (=habit forming), and lacking the chance to play proper games (which nowadays means the better indies), which many people do, it's the next best alternative. Especially since I believe that the supermajority of gacha players doesn't engage with their, err... idiosyncratic communities at all.