It's really just business. Gacha is gambling with attachment. It's different from pachislot, because it uses FOMO, it preys on attachment or attraction to a design. There are stories of FGO players flying to France to roll of Jean D'Arc. People whaling for faves with 1% rates.
When we talk about gacha, we don't talk about that. We don't talk about the people prone to depression, hyper-fixation, and mental health problems that easily become prey to these other means of stoking or creating businesses.
I'm speaking from personal experience. I spent over €350 at a chance to get a character with a 1% drop rate because I was extremely depressed and wanted to be happy because of an extremely low low I was having as a result of my mental illness.
Thankfully I was in a position where I was able to get help after months of this behavior. (Medication, re-diagnosis) Not everyone is that lucky. Gacha shouldn't be normalized or folded into how we interact with games, I say this as someone who /still/ plays gacha.
The only reason rates started showing up in gacha games was because the previous system was causing stocks to drop in value in certain companies. It's business, and by extension it is a business that will always seek to exploit consumers for profit through attachment and impulse.
Modern gacha is a symptom of the industry and we should be evaluating that.