When you draw a parallel to social charity both are largely volunteer based and underfunded. And both have direct and indirect gains for society.
Physical charity often serves basic needs. I'm not sure selecting qualifying quality open source projects is as easy. Need and gain assessments are a lot less clear.
If it's about public funding distribution, I would like to see some FOSS funding too, but not at the cost of or equal or more than social projects.
How many FOSS projects actually benefit "millions and billions of people"? That kind of impact feels like it's few and far between.
But did it reach test or production environment yet? Or will it die in development environment.