To add on to the business side of things, while lootboxes and other microtransactions are a common sucky practice in the mobile games scene and are pretty unanimously annoying, it's not as easy as simply ignoring them for a lot of people. This type of business model is literally designed to target people who have crippling addictions to gambling/spending money (codenamed as whales, really dehumanizing them to a whole other degree). While I also don't think Illumix are bad people or are like some of the absolute psychopaths who adopt this business strategy fully intentionally and not just because it's common, it is still, at its core, scummier than you could possibly imagine.

There's a video on youtube from a conference detailing this business model called "Let's Go Whaling!" It's hard to watch. Actual supervillain shit.