Unity’s runtime fee will be collected once a game “has passed a minimum revenue threshold in the last 12 months” and “has passed a minimum lifetime install count,” according to the blog post.
Unity Personal and Unity Plus customers must pay $0.20 per install after reaching $200,000 of revenue in the past year and having more than 200,000 lifetime game installs.
Unity Pro and Unity Enterprise users will pay $0.15 and $0.125 per install, respectively, after making $1 million in the past year and having more than 1 million lifetime game installs. (Those fees will decrease as higher thresholds are met.)
You literally pay less the richer you are. Most efficient system.
Thankfully the retroactive bit was dropped, but Jesus what a horrible decision. Really sucks that Unreal is also complete trash for 2D development (which is the main indie environment), but at least Godot got more devs.
Unity has been unprofitable forever and they have to try to get their pound of flesh eventually. Godot has no such problem. For something like game engines getting something FOSS to a good place makes sense for the industry in the long run.