> Can you prove you're right?

:) I thought so.

The only people making arguments about future Unity changes were Open Source weirdos like me who were warning against proprietary software in general, and we were regularly dismissed and called impractical. Nobody was considering that Unity would drop revenue sharing as a business model. If you go back and look at advice about the mobile markets, this was not a concern on anybody's mind.

Yes, people considered that pricing itself might change, but professionals in industry were not advising about the possibility of Unity changing away from a revenue share model, nor was this ever coming up as a concern in conversations about Unity's efforts to appeal to mobile developers. It's actually fairly easy to tell what people were thinking about Unity's pricing model given how recent the change is -- you can just go back and look at the many conversations people were having about engines.

I'll tell you what you won't see: you won't see a lot of people floating the possibility of installation-based pricing.

> I don't see any evidence that Unity made guarantees that it's historical prices would remain consistent into the future.

This isn't about a pricing change, it's about a change to the entire pricing model.

Nonetheless, you raise a good point. Unity could make arbitrary changes in the future as well. Doubtless, you would agree that it's irresponsible for devs today to use Unity under the current terms given that they have no control over what Unity's future pricing will be and given that pricing changes can be retroactively applied to games that they release before those changes?

Certainly you'd advocate today for the same level of responsibility and caution that you're arguing mobile developers should have had in the past, right? We have no idea what Unity's pricing model will be in 6 months, there's no guarantees in the contract -- and like you say, we need to consider that fact when building a business. So it would be the height of irresponsibility to advocate that everything is fine and the changes are no big deal and developers should just continue to use Unity.

Would you advise Unity developers today to decrease reliance on the engine and to be extremely cautious about building a business on top of a platform that can make arbitrary changes to pricing structures and that can apply those changes to existing products? Sure Vampire Survivors is profitable now, but as you correctly point out, there's nothing in the contract stopping Unity from changing that in the future.

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> So not only can you predict what I would say, you have some sort of insights into Unity's cost structures and what it requires for them to keep Unity updated and competitive?

Scary, right? I'm almost as psychic as you expect mobile developers should have been. ;) In my case it's not magic though, there's a trick to it. I get my information from having being active in game development spaces for a while and being familiar with the conversations that professionals were having about engine choice, and also from reading Unity's own press release and reading their own supplied justifications for why they're making the change.

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> If my costs of goods increase but I keep my prices the same, it's my fault

For anyone unfamiliar with how F2P and ad-supported games work, you can't just increase the cost of purchase for them, that's not really a thing, ad-supported games don't have a purchase cost to increase.