Cardano was already designed with sustainability in mind. The point was to create a system that governs and also finances itself without being dependent on donations. Cardano has a built-in treasury system that gets a constant stream of funds from transaction fees and treasury taxes. This is explained in detail in treasuries with Bingsheng Zhang.
Project Catalyst, Cardano's innovation platform is the current way to access the funds of the treasury system. It is seen as a stepping stone to Voltaire and aims to provide a safe and lively environment to explore the highest potential of human collaboration.