Unity announced a new fee structure today, and developers are none too happy. “We are introducing a Unity Runtime Fee that is based upon each time a qualifying game is downloaded by an end user,” the company wrote in a blog post announcing the change. “We chose this because each time a game is downloaded, the Unity Runtime is also installed.” The new per-install fees are set to kick in on January 1, 2024.
AFAIK this applies retroactively.
Unfortunately, I was just coming back to comment this myself, and link this: https://www.gamingonlinux.com/2023/09/unity-attempt-to-clarify-new-install-fees-as-developers-revolt/