What does it mean for a mathematics to be "provisioned"? A well-funded math foundation run like the Linux Foundation could cover the lifestyles of many elite mathematicians. I don't understand why you imagine it would be centralized behind one "large entity" or that this large entity, so long as it is not a government, can't be trusted to fund good things.
People unaffiliated with the Linux foundation contribute to Linux. Regularly.
For a public good to be provisioned means that the necessary resources and organization for that good, need to be supplied.
Supporting a group of elite mathematicians is not enough. There needs to be a path to becoming an elite mathematician.
Which either means that it becomes an unpaid hobby. Or there is some wider source of support for the profession.