Why does critical open source software still depend on one exhausted maintainer?

In November 2025, Kubernetes retired Ingress NGINX, one of its most widely deployed components, not because it was superseded but because the volunteer maintainer team could no longer sustain it. Separately, External Secrets Operator, used in critical enterprise pipelines globally, froze all updates when four of its five maintainers burned out simultaneously. Industry surveys now show 60 percent of open source maintainers work unpaid and 44 percent cite burnout as the reason they left or considered leaving. Funding programs like Open Source Pledge and GitHub Sponsors exist but address money, not the actual bottleneck, which is the review queue. There is no lightweight, automated system that durably transfers working context, test coverage expectations, and threat-model knowledge from an exiting maintainer to a successor, so each departure resets a project close to zero.