Unity has changed its pricing model

Popular video game engine Unity is making big changes to its pricing structure that's causing confusion and anger among developers. On Tuesday, Unity announced that on January 1st, 2024, it would be implementing a pay-per-download pricing scheme that would charge developers a flat fee any time a game using Unity software is installed.
The news was met with fear, anger, and disgust from the game development community. The primary complaint is that these changes would be particularly harmful to solo, indie, marginalized, and mobile developers.
Of particular note is the fact that Unity is assessing these fees based on the number of installs a game has without seeming to account for the many reasons, legal or illegal, a game might have multiple installs without multiple purchases. After a game meets the revenue threshold, if its downloads far outstrip its revenue generation, a developer will be on the hook to pay. Pirated games, demos, games downloaded across multiple devices, and games offered on subscription services like Game Pass are all potentially affected by these new fees.
Additionally, there's the concern that malicious actors could use this information to run up charges by continuously downloading and redownloading games as a form of protest or griefing.
an extra fee will be charged if a user installs a game on a second device, say a Steam Deck after installing a game on a PC.
Developers have also noted that Unity is implementing this new fee structure on top of charging yearly subscription fees while removing cheaper tiers and shunting developers into higher, more expensive ones. Embedded in today's announcement was also the news that Unity would no longer be offering the Unity Plus subscription tier.
Developers are also concerned these new fees could impact digital preservation efforts as now game makers are seemingly incentivized to delist older games so they aren't charged for them. There's also the question of how Unity plans on tracking installs and whether or not such tools run afoul of government privacy laws. Here's a tweet from the official Unity account explaining how it intends to monitor a game's installs.