I do not think this is a place for consumer action. It is good the devs are running their awareness campaign for gamers. If a dev releases a game made in Unity in 2025 it is because they have made the decision that it is the best course of action for their business. Maybe they have a B2P or subscription model that makes the runtime cost more sustainable over throwing out N years for development effort.
At the end of the day Unity is a business to business product. The developers are the customer, not the players. If Unity's new pricing and business practices don't make sense to developers then developers will no longer use it and Unity will fail without player intervention.
I don't think your goal is to further hurt the devs. Boycotting games made with Unity is throwing the baby out with the bath water.
Wayland has a mouse capture bug in proton / wine. It particularly seems to be an issue in FPS games. That may contributing to slower adoption for Linux gamers.
https://github.com/ValveSoftware/Proton/issues/7564