It is opensource so there is still a lot of volunteer work going on there but the infrastructure (CI/CD, image hosting, etc) is also paid for by corporations and not by the community. Its millions of dollars a year in contributions.
i wouldn't really call $400k/year in total "heavily subsidized", that's around the all in cost of a single developer at one of these sponsoring companies
- https://k8s.devstats.cncf.io/d/9/companies-table?orgId=1
It is opensource so there is still a lot of volunteer work going on there but the infrastructure (CI/CD, image hosting, etc) is also paid for by corporations and not by the community. Its millions of dollars a year in contributions.