Actually, one of the reasons Genshin is lauded by it's player base is that you can clear the hardest content with free to play characters. The 5 stars have way

Actually, one of the reasons Genshin is lauded by it's player base is that you can clear the hardest content with free to play characters. The 5 stars have way flashier looking abilities and get more face-time in the narrative, and are generally a bit more meta, but are not leaps and bounds stronger. So Genshin has at least proven that "selling broken OP characters" is not a necessary ingredient to making a $2B hit. That said, other gacha games are definitely all about selling that power.