I can't fathom the logic. Why not do a slice of revenue like Unreal does, and calibrate the percentage so you make the same amount of money as you would have otherwise made had you done it per-install? Happier customers and identical revenue.
I mean, how can you not see that? Or was the thinking, screw that market, we are only catering for AAA games now? Even then it makes little sense as the revenue share like Unreal does, would make more money.
It likeley was something along the lines of: "they need us, they will have to find a way to pay us, if they want to continue existing."
Indies are a necessary casualty in the eyes of Unity (or more accurately: they're just not considered).
Unity is the engine behind some of the most popular mobile gacha games. MiHoYo (Genshin/Honkai Impact) uses it for everything, so does Type/Moon (Fate Grand Order). They want a slice of that pie. That's where the real money is. Those games rake in hundreds of millions of dollars every month.
Hence also why the charge is by install and can be waived if you use Unity's adtech offerings.
For 90-95% if not more of their users the financial aspect is not such a big deal. The way they announced it and planning to implement (retroactively and how do they even track “installs”) is a way bigger issue.
I worked as a community manager for a free-to-play mobile gaming company in the US about 10+ years ago.
The gacha mechanic just absolutely ruined games for normal, everyday users. You had random moms and grandmas write in with the sweetest messages asking for features or reporting a bug.
For the most part, their feedback and requests went right into the garbage can.
Meanwhile, we had people from Qatar, Saudi Arabia, and Singapore spending $40K USD per week on in app purchases.
Gacha is effectively gambling and exploiting users' propensities for addictive behavior. We would jokingly call it the "Gotch Ya!" mechanic.
Feature roadmaps, bug fixes and A/B tests were all about "optimizing the funnel" -- i.e., how do we get these whales to spend more money or more parts of the app.
Good god, it was so demoralizing.
China (and some other countries). They won’t declare their full revenue and you won’t be able to find it out, it’s expensive to admin and there is hardly any legal recourse anyway.
Also their biggest clients would probably hate rev. share even more than this.